Publications

@article{https://doi.org/10.1002/anie.202501854,

title = {Plasmonic-Hydrogel Hybrid Biomaterials Via In Situ Seeded Growth},

author = {Gail A. Vinnacombe-Willson and Manuel Núñez-Martínez and Ada Herrero-Ruiz and Francisco Bevilacqua and Raquel Pazos and Lara Troncoso-Afonso and Marta Gallego-González and Leonardo Scarabelli and Luis M. Liz-Marzán},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202501854},

doi = {https://doi.org/10.1002/anie.202501854},

year  = {2025},

date = {2025-04-11},

urldate = {2025-04-11},

journal = {Angewandte Chemie International Edition},

volume = {n/a},

number = {n/a},

pages = {e202501854},

abstract = {Abstract The combination of hydrogels and functional plasmonic metal nanoparticles affords the development of unique hybrid systems, such as actuators, biosensors, and drug delivery systems, among others. Being typically prepared in colloidal suspension, incorporating shape-controlled plasmonic nanoparticles on polymer substrates typically requires lengthy processes involving synthesis, washing, and self-assembly. We report an alternative, robust in situ seed-mediated growth method whereby either isotropic or anisotropic gold and silver nanoparticles can be prepared directly on gelatin-based hydrogels, taking advantage of the polymer's native chemical functionalities. In-depth characterization of gold precursor–polymer interactions enabled the rational growth of branched gold nanoparticles on biocompatible hydrogels with different physicochemical properties. In situ seeded growth circumvents traditional limitations imposed by the need for colloidal stability, thereby enabling gold nanoparticle synthesis under surfactant-free conditions and in high ionic strength solutions, thus enhancing their suitability for applications involving live cells. This method can be expanded to create libraries of hybrid plasmonic materials with potential impact in the fabrication of functional 3D cell culture substrates, as well as biological and chemical sensors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/cnma.202300566,

title = {Colloidal Plasmonic Metasurfaces for the Enhancement of Non-Linear Optical Processes and Molecular Spectroscopies},

author = {Ylli Conti and Naihao Chiang and Leonardo Scarabelli},

url = {https://aces.onlinelibrary.wiley.com/doi/abs/10.1002/cnma.202300566},

doi = {https://doi.org/10.1002/cnma.202300566},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {ChemNanoMat},

volume = {10},

number = {4},

pages = {e202300566},

abstract = {Abstract Colloidal metasurfaces are emerging as promising candidates for the development of functional chemical metamaterials, combining the undisputed control over crystallography and surface chemistry achieved by synthetic nanochemistry with the scalability and versatility of colloidal self-assembly strategies. In light of recent reports of colloidal plasmonic materials displaying high-performing optical cavities, this Minireview discusses the use of this type of metamaterials in the specific context of non-linear optical phenomena and non-linear molecular spectroscopies. Our attention is focused on the opportunities and advantages that colloidal nanoparticles and self-assembled plasmonic metasurfaces can bring to the table compared to more traditional nanofabrication strategies. Specifically, we believe that future work in this direction will express the full potential of non-linear molecular spectroscopies to explore the chemical space, with a deeper understanding of plasmon-molecule dynamics, plasmon-mediated processes, and surface-enhanced chemistry.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adom.202300983,

title = {Colloidal Silver Nanoparticle Plasmonic Arrays for Versatile Lasing Architectures via Template-Assisted Self-Assembly},

author = {Ylli Conti and Nicolas Passarelli and Jose Mendoza-Carreño and Leonardo Scarabelli and Agustin Mihi},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202300983},

doi = {https://doi.org/10.1002/adom.202300983},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Advanced Optical Materials},

volume = {11},

number = {23},

pages = {2300983},

abstract = {Abstract The characteristic narrow spectral features of surface lattice resonances emerge as great candidates for the rational design of optical nanocavities targeting enhanced light-matter interaction, ultrasensitive detection, or efficient light-energy conversion. Traditional fabrication of metal arrays involves thermal evaporation and annealing steps, limiting scalability and adaptability. In contrast, template-assisted self-assembly provides a high-throughput all-around approach for implementing colloidal plasmonic metasurfaces on a variety of different materials. Here, the use of pre-synthesized silver nanoparticles is designed and tested for the construction of versatile lasing architectures. Plasmonic arrays are prepared directly on top of the gain media (a photoresist thin film doped with Rhodamine B), creating optical nanocavities with quality factors as high as 85. The proposed architecture circumvents the need for an index-matching superstrate to promote the generation of collective resonances, leaving the plasmonic surface accessible for post-assembly modification. Additionally, the angular dispersion of the metasurfaces is used to modify the angle of the lasing emission, achieving both normal and off-normal lasing upon modification of the lattice parameter of the array. The results demonstrate how state-of-the-art colloidal self-assembly techniques offer a scalable and versatile alternative for the fabrication of plasmonic and photonic devices targeting advanced and non-linear optical phenomena.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.chemrev.2c00914,

title = {Direct Bottom-Up In Situ Growth: A Paradigm Shift for Studies in Wet-Chemical Synthesis of Gold Nanoparticles},

author = {Gail A. Vinnacombe-Willson and Ylli Conti and Andrei Stefancu and Paul S. Weiss and Emiliano Cortés and Leonardo Scarabelli},

url = {https://doi.org/10.1021/acs.chemrev.2c00914},

doi = {10.1021/acs.chemrev.2c00914},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Chemical Reviews},

volume = {123},

number = {13},

pages = {8488-8529},

abstract = {Plasmonic gold nanoparticles have been used increasingly in solid-state systems because of their applicability in fabricating novel sensors, heterogeneous catalysts, metamaterials, and thermoplasmonic substrates. While bottom-up colloidal syntheses take advantage of the chemical environment to control size, shape, composition, surface chemistry, and crystallography of the nanostructures precisely, it can be challenging to assemble nanoparticles rationally from suspension onto solid supports or within devices. In this Review, we discuss a powerful recent synthetic methodology, bottom-up in situ substrate growth, which circumvents time-consuming batch presynthesis, ligand exchange, and self-assembly steps by applying wet-chemical synthesis to form morphologically controlled nanostructures on supporting materials. First, we briefly introduce the properties of plasmonic nanostructures. Then we comprehensively summarize recent work that adds to the synthetic understanding of in situ geometrical and spatial control (patterning). Next, we briefly discuss applications of plasmonic hybrid materials prepared by in situ growth. Overall, despite the vast potential advantages of in situ growth, the mechanistic understanding of these methodologies remains far from established, providing opportunities and challenges for future research.},

note = {PMID: 37279171 

Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsanm.3c00440,

title = {Exploring the Bottom-Up Growth of Anisotropic Gold Nanoparticles from Substrate-Bound Seeds in Microfluidic Reactors},

author = {Gail A. Vinnacombe-Willson and Joy K. Lee and Naihao Chiang and Leonardo Scarabelli and Shouzheng Yue and Ruth Foley and Isaura Frost and Paul S. Weiss and Steven J. Jonas},

url = {https://doi.org/10.1021/acsanm.3c00440},

doi = {10.1021/acsanm.3c00440},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {ACS Applied Nano Materials},

volume = {6},

number = {8},

pages = {6454-6460},

abstract = {We developed an unconventional seed-mediated in situ synthetic method, whereby gold nanostars are formed directly on the internal walls of microfluidic reactors. The dense plasmonic substrate coatings were grown in microfluidic channels with different geometries to elucidate the impacts of flow rate and profile on reagent consumption, product morphology, and density. Nanostar growth was found to occur in the flow-limited regime and our results highlight the possibility of creating shape gradients or incorporating multiple morphologies in the same microreactor, which is challenging to achieve with traditional self-assembly. The plasmonic–microfluidic platforms developed herein have implications for a broad range of applications, including cell culture/sorting, catalysis, sensing, and drug/gene delivery.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.chemrev.3c00033,

title = {Plate-Like Colloidal Metal Nanoparticles},

author = {Leonardo Scarabelli and Muhua Sun and Xiaolu Zhuo and Sungjae Yoo and Jill E. Millstone and Matthew R. Jones and Luis Liz-Marzán},

url = {https://doi.org/10.1021/acs.chemrev.3c00033},

doi = {10.1021/acs.chemrev.3c00033},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Chemical Reviews},

volume = {123},

number = {7},

pages = {3493-3542},

abstract = {The pseudo-two-dimensional (2D) morphology of plate-like metal nanoparticles makes them one of the most anisotropic, mechanistically understood, and tunable structures available. Although well-known for their superior plasmonic properties, recent progress in the 2D growth of various other materials has led to an increasingly diverse family of plate-like metal nanoparticles, giving rise to numerous appealing properties and applications. In this review, we summarize recent progress on the solution-phase growth of colloidal plate-like metal nanoparticles, including plasmonic and other metals, with an emphasis on mechanistic insights for different synthetic strategies, the crystallographic habits of different metals, and the use of nanoplates as scaffolds for the synthesis of other derivative structures. We additionally highlight representative self-assembly techniques and provide a brief overview on the attractive properties and unique versatility benefiting from the 2D morphology. Finally, we share our opinions on the existing challenges and future perspectives for plate-like metal nanomaterials.},

note = {PMID: 36948214 

Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/anie.202217614,

title = {Towards Electrochemiluminescence Microscopy Exploration of Plasmonic-Mediated Phenomena at the Single-Nanoparticle Level},

author = {Leonardo Scarabelli},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202217614},

doi = {https://doi.org/10.1002/anie.202217614},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Angewandte Chemie International Edition},

volume = {62},

number = {13},

pages = {e202217614},

abstract = {Abstract The rational design of functional plasmonic metasurfaces and metamaterials requires the development of high-throughput characterization techniques compatible with operando conditions and capable of addressing single-nanostructures. In their work, Wei et al. demonstrate the use of electrochemiluminescence microscopy to investigate the mechanism behind plasmon-enhanced luminescence induced by gold nanostructures. The use of gold plasmonic arrays was exploited to achieve the rapid spectroscopic evaluation of all the individual nanostructures, and the correlation of the results with high- resolution electron microscopy analysis, guaranteeing a strict one-to-one correspondence. The authors were able to identify two different mechanisms for the enhancement of [Ru(bpy)3]2+-tri-n-propylamine electrochemiluminescence mediated by single gold nanoparticles and by small plasmonic clusters. In the future, the proposed characterization could be used for the rapid and in situ spectroscopic analysis of more complex plasmonic nanostructures and metasurfaces.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adom.202102635,

title = {Robust Encapsulation of Biocompatible Gold Nanosphere Assemblies for Bioimaging via Surface Enhanced Raman Scattering},

author = {Marius Schumacher and Dorleta Jimenez Aberasturi and Jan-Philip Merkl and Leonardo Scarabelli and Elisa Lenzi and Malou Henriksen-Lacey and Luis Liz-Marzán and Horst Weller},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202102635},

doi = {https://doi.org/10.1002/adom.202102635},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Advanced Optical Materials},

volume = {10},

number = {14},

pages = {2102635},

abstract = {Abstract Controlled assembly of gold nanoparticles (AuNPs) into clusters is a promising avenue for the development of sensitive bioimaging and diagnostic tools based on surface-enhanced Raman scattering (SERS). However, several challenges, such as biocompatibility or colloidal and structural stability in biological environments, remain before AuNPs can be used as a tool for in vivo bioimaging. A versatile strategy for the preparation of colloidally stable and biocompatible AuNP clusters (AuNPCs) is introduced with high SERS signals, which are used as SERS contrast bioimaging agents (SERS tags). By tuning the ligand ratio of Raman reporter molecules to stabilizing polymer on the surface of each AuNP, aggregation can be carefully controlled. The resulting AuNPCs exhibit redshifted surface plasmon resonances in the near-infrared (NIR) region, as well as distinct electromagnetic hotspots that give rise to SERS analytical enhancement factors above 104, compared to non-clustered spherical AuNPs. Thanks to the protective polymer shell, high levels of cellular uptake with low cytotoxicity are observed, allowing 3D SERS mapping of cells with sufficiently high spatial resolution to detect AuNPCs within intracellular organelles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{D2TC01148D,

title = {Pre- and post-assembly modifications of colloidal plasmonic arrays: the effect of size distribution, composition and annealing},

author = {Oriol Colomer-Ferrer and Serni Toda Cosi and Ylli Conti and David E. Medina-Quiroz and Leonardo Scarabelli and Agustin Mihi},

url = {http://dx.doi.org/10.1039/D2TC01148D},

doi = {10.1039/D2TC01148D},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {J. Mater. Chem. C},

volume = {10},

issue = {37},

pages = {13913-13921},

publisher = {The Royal Society of Chemistry},

abstract = {Templated self-assembly has emerged as one of the most versatile approaches for the fabrication of plasmonic ordered arrays composed of colloidal nanoparticle clusters, representing a valid alternative to top-down lithography for the scalable and low-cost production of this type of plasmonic substrates. Templated self-assembly can be applied to a variety of materials, solvents, and colloidal size, shape, and composition. A higher degree of control over the preparation of the colloids and their assembly would enable the rational modification of the internal composition and architecture of the repeating units of the array, targeting specific properties and applications. In this work, we explored both pre- and post-assembly modifications of the plasmonic system, analyzing their effect on the resulting collective optical properties. Combining both gold nanoparticles of different sizes and mixtures of gold and silver colloids, we demonstrated the possibility of leveraging near- and far-field coupling to control the optical losses of the system. Moreover, we explored the application of a thermal annealing step to induce the sintering of the colloidal building blocks within the plasmonic clusters. At lower temperatures (300 °C), the resulting single plasmonic objects are characterized by an inhomogeneous elemental distribution, while atomic migration and formation of alloys is triggered at higher temperatures (450 °C). By systematically analyzing the effect of the annealing we show an improvement in lattice plasmonic resonance quality factor of a gold nanoparticle array by 20%, without compromising its characteristic chemical and physical stability. Collectively, our results establish intriguing directions for the preparation of plasmonic arrays where the repeating unit can be engineered either before or after the assembly targeting specific catalytic, optical or magnetic properties.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adma.202205330,

title = {Surface Lattice Plasmon Resonances by Direct In Situ Substrate Growth of Gold Nanoparticles in Ordered Arrays},

author = {Gail A. Vinnacombe-Willson and Ylli Conti and Steven J. Jonas and Paul S. Weiss and Agustín Mihi and Leonardo Scarabelli},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202205330},

doi = {https://doi.org/10.1002/adma.202205330},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Advanced Materials},

volume = {34},

number = {37},

pages = {2205330},

abstract = {Abstract Precise arrangements of plasmonic nanoparticles on substrates are important for designing optoelectronics, sensors and metamaterials with rational electronic, optical and magnetic properties. Bottom-up synthesis offers unmatched control over morphology and optical response of individual plasmonic building blocks. Usually, the incorporation of nanoparticles made by bottom-up wet chemistry starts from batch synthesis of colloids, which requires time-consuming and hard-to-scale steps like ligand exchange and self-assembly. Herein, an unconventional bottom-up wet-chemical synthetic approach for producing gold nanoparticle ordered arrays is developed. Water-processable hydroxypropyl cellulose stencils facilitate the patterning of a reductant chemical ink on which nanoparticle growth selectively occurs. Arrays exhibiting lattice plasmon resonances in the visible region and near infrared (quality factors of >20) are produced following a rapid synthetic step (<10 min), all without cleanroom fabrication, specialized equipment, or self-assembly, constituting a major step forward in establishing in situ growth approaches. Further, the technical capabilities of this method through modulation of the particle size, shape, and array spacings directly on the substrate are demonstrated. Ultimately, establishing a fundamental understanding of in situ growth has the potential to inform the fabrication of plasmonic materials; opening the door for in situ growth fabrication of waveguides, lasing platforms, and plasmonic sensors.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/accountsmr.1c00106,

title = {Templated Colloidal Self-Assembly for Lattice Plasmon Engineering},

author = {Leonardo Scarabelli and David Vila-Liarte and Agustín Mihi and Luis Liz-Marzán},

url = {https://doi.org/10.1021/accountsmr.1c00106},

doi = {10.1021/accountsmr.1c00106},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Accounts of Materials Research},

volume = {2},

number = {9},

pages = {816-827},

abstract = {ConspectusOver the past 30 years, the engineering of plasmonic resonances at the nanoscale has progressed dramatically, with important contributions in a variety of different fields, including chemistry, physics, biology, engineering, and medicine. However, heavy optical losses related to the use of noble metals for the fabrication of plasmonic structures hindered their application in various settings. Recently, an answer to these long-lasting issues emerged in the use of lattice plasmon resonances (LPRs, also called surface lattice resonances), bringing new excitement in the field of plasmonics. Specifically, the organization of plasmonic nanoparticles into ordered arrays enables far-field coupling of the scattered light exploiting the diffraction modes of the array, generating plasmonic resonances with bandwidths as narrow as a few nanometers, corresponding to an increase of over 10-fold in the quality factors compared to localized plasmon resonances. As such, LPRs offer new opportunities to harness light–matter interactions at the nanoscale, while generating renewed interest in the self-assembly of colloidal metal nanoparticles, as a scalable approach to the preparation of such plasmonic arrays. Templated self-assembly emerged as one of the most versatile approaches, being compatible with soft-lithographic techniques such as nanoimprint lithography and amenable to a variety of materials, colloids, and solvents. Templated self-assembly additionally allows the preparation of arrays where the repeating units are composed of multiple self-assembled nanoparticles (i.e., plasmonic clusters). In this system, near-field coupling can be finely tuned, thereby showing promising results in biosensing, catalysis, or plasmonic heating. In this Account, we review the preparation of ordered arrays of clusters of plasmonic nanoparticles. We present various aspects involved in the templated self-assembly of colloidal nanoparticles, with the aim of achieving at the same time close-packed structures within each cavity of the template, and uniform deposition over a large area. We then analyze the optical properties of the prepared substrates. The preparation of hierarchical structures and the possibility of tuning both the internal structure of the cluster and their organization into arrays with different lattice parameters enable control over both near-field and far-field plasmonic coupling. This unique feature of such substrates makes it possible to exploit the interplay between these two types of coupling, for the preparation of versatile functional substrates, expanding the possibilities for the integration of plasmonic arrays into functional devices for various applications. A well-established example is their use for surface-enhanced Raman scattering. On the other hand, optimization of far-field coupling provides access to plasmonic cavities for lasing or refractive index sensing. Despite two decades of fervid scientific research, the preparation and engineering of plasmonic arrays remains a relevant topic, and many directions remain largely unexplored. We conclude with a collection of perspectives and challenges that we find particularly stimulating toward future developments of the field.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adom.202100761,

title = {Engineering Plasmonic Colloidal Meta-Molecules for Tunable Photonic Supercrystals},

author = {Pau Molet and Nicolás Passarelli and Luis A. Pérez and Leonardo Scarabelli and Agustín Mihi},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202100761},

doi = {https://doi.org/10.1002/adom.202100761},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Advanced Optical Materials},

volume = {9},

number = {20},

pages = {2100761},

abstract = {Abstract Ordered arrays of metal nanoparticles offer new opportunities to engineer light–matter interactions through the hybridization of Rayleigh anomalies and localized surface plasmons. The generated surface lattice resonances exhibit much higher quality factors compared to those observed in isolated metal nanostructures. Template-induced colloidal self-assembly has already shown a great potential for the scalable fabrication of 2D plasmonic meta-molecule arrays, but the experimental challenge of controlling optical losses within the repeating units has so far prevented this approach to compete with more standard fabrication methods in the production of high-quality factor resonances. In this manuscript, the optical properties of plasmonic arrays are investigated by varying the lattice parameter (between 200 and 600 nm) as well as the diameter of the gold colloidal building-blocks (between 11 ± 1 and 98 ± 6 nm). It is systematically studied how the internal architecture of the repeating gold-nanoparticle meta-molecules influences the optical response of the plasmonic supercrystals. Combining both experimental measurements and simulations, it is demonstrated how, reducing the size of the gold nanoparticles it is possible to switch from strong near-field plasmonic architectures to high-quality factors (>60) for lattice plasmon resonances located in the visible spectral range.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsmaterialslett.0c00535,

title = {Large-Scale Soft-Lithographic Patterning of Plasmonic Nanoparticles},

author = {Naihao Chiang and Leonardo Scarabelli and Gail A. Vinnacombe-Willson and Luis A. Pérez and Camilla Dore and Agustín Mihi and Steven J. Jonas and Paul S. Weiss},

url = {https://doi.org/10.1021/acsmaterialslett.0c00535},

doi = {10.1021/acsmaterialslett.0c00535},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {ACS Materials Letters},

volume = {3},

number = {3},

pages = {282-289},

abstract = {Micro- and nanoscale patterned monolayers of plasmonic nanoparticles were fabricated by combining concepts from colloidal chemistry, self-assembly, and subtractive soft lithography. Leveraging chemical interactions between the capping ligands of pre-synthesized gold colloids and a polydimethylsiloxane stamp, we demonstrated patterning gold nanoparticles over centimeter-scale areas with a variety of micro- and nanoscale geometries, including islands, lines, and chiral structures (e.g., square spirals). By successfully achieving nanoscale manipulation over a wide range of substrates and patterns, we established a powerful and straightforward strategy, nanoparticle chemical lift-off lithography (NP-CLL), for the economical and scalable fabrication of functional plasmonic materials with colloidal nanoparticles as building blocks, offering a transformative solution for designing next-generation plasmonic technologies.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.jchemed.0c01150,

title = {Seeded-Growth Experiment Demonstrating Size- and Shape-Dependence on Gold Nanoparticle–Light Interactions},

author = {Gail A. Vinnacombe-Willson and Naihao Chiang and Paul S. Weiss and Sarah H. Tolbert and Leonardo Scarabelli},

url = {https://doi.org/10.1021/acs.jchemed.0c01150},

doi = {10.1021/acs.jchemed.0c01150},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Chemical Education},

volume = {98},

number = {2},

pages = {546-552},

abstract = {Gold nanoparticles are exciting materials in nanotechnology and nanoscience research and are being applied across a wide range of fields including imaging, chemical sensing, energy storage, and cancer therapies. In this experiment, students will synthesize two sizes of gold nanospheres (∼20 and ∼100 nm) and will create gold nanostars utilizing a seed-mediated growth synthetic approach. Students will compare how each sample interacts differently with light (absorption and scattering) based on the nanoparticles’ size and shape. This experiment is ideal for high school and early undergraduate students since all reagents are nontoxic and affordable, and no special characterization equipment is required.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acsnano.1c10538b,

title = {An Extended Protocol for the Synthesis of Monodisperse Gold Nanotriangles},

author = {Leonardo Scarabelli and Luis Liz-Marzán},

url = {https://doi.org/10.1021/acsnano.1c10538},

doi = {10.1021/acsnano.1c10538},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {ACS Nano},

volume = {15},

number = {12},

pages = {18600-18607},

abstract = {Anisotropic plasmonic nanoparticles have found applications in a wide range of scientific and technological fields, including medicine, energy storage and production, ultrasensitive sensing, catalysis, and photonics. These colloids owe their all-around success in such different scenarios to the development of rapid, scalable, and rational synthetic schemes. Gold nanotriangles (AuNTs), geometrically termed truncated triangular bipyramids, have attracted the attention of the scientific community because of their combination of well-defined crystallography, anisotropic plasmon spatial distribution, sharp tips that favor the generation of high electric fields, atomically flat surfaces, and a wide spectral tunability within the visible and infrared ranges combined with narrow bandwidths of their plasmon resonances. In this context, we previously reported a procedure for the production of AuNTs, based on a seed-mediated approach that guarantees batch-to-batch reproducibility in both size (within 5 nm in edge-length) and extinction spectra (down to 1 nm precision). The protocol involves numerous synthetic steps, and reproducibility requires awareness and familiarity with several details, which are usually learned through practice and repetition and may not always be intuitive on the basis of standard experimental protocols. We provide herein an enhanced protocol with full details and demonstration videos, which we expect will further foster the utilization of this fascinating type of anisotropic nanomaterials by researchers who are less experienced in the preparation and handling of gold colloids.},

note = {PMID: 34866398 

Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.nanolett.0c04667,

title = {Can Copper Nanostructures Sustain High-Quality Plasmons?},

author = {Vahagn Mkhitaryan and Katia March and Eric Nestor Tseng and Xiaoyan Li and Leonardo Scarabelli and Luis Liz-Marzán and Shih-Yun Chen and Luiz H. G. Tizei and Odile Stéphan and Jenn-Ming Song and Mathieu Kociak and F. Javier García Abajo and Alexandre Gloter },

url = {https://doi.org/10.1021/acs.nanolett.0c04667},

doi = {10.1021/acs.nanolett.0c04667},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Nano Letters},

volume = {21},

number = {6},

pages = {2444-2452},

abstract = {Silver, king among plasmonic materials, features low inelastic absorption in the visible-infrared (vis-IR) spectral region compared to other metals. In contrast, copper is commonly regarded as too lossy for actual applications. Here, we demonstrate vis-IR plasmons with quality factors >60 in long copper nanowires (NWs), as determined by electron energy-loss spectroscopy. We explain this result by noticing that most of the electromagnetic energy in these plasmons lies outside the metal, thus becoming less sensitive to inelastic absorption. Measurements for silver and copper NWs of different diameters allow us to elucidate the relative importance of radiative and nonradiative losses in plasmons spanning a wide spectral range down to <20 meV. Thermal population of such low-energy modes becomes significant and generates electron energy gains associated with plasmon absorption, rendering an experimental determination of the NW temperature. Copper is therefore emerging as an attractive, cheap, abundant material platform for high-quality plasmonics in elongated nanostructures.},

note = {PMID: 33651617},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acscentsci.0c01097,

title = {In Situ Shape Control of Thermoplasmonic Gold Nanostars on Oxide Substrates for Hyperthermia-Mediated Cell Detachment},

author = {Gail A. Vinnacombe-Willson and Naihao Chiang and Leonardo Scarabelli and Yuan Hu and Liv K. Heidenreich and Xi Li and Yao Gong and Derek T. Inouye and Timothy S. Fisher and Paul S. Weiss and Steven J. Jonas},

url = {https://doi.org/10.1021/acscentsci.0c01097},

doi = {10.1021/acscentsci.0c01097},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {ACS Central Science},

volume = {6},

number = {11},

pages = {2105-2116},

abstract = {Gold nanostars (AuNSTs) are biocompatible, have large surface areas, and are characterized by high near-infrared extinction, making them ideal for integration with technologies targeting biological applications. We have developed a robust and simple microfluidic method for the direct growth of anisotropic AuNSTs on oxide substrates including indium tin oxide and glass. The synthesis was optimized to yield AuNSTs with high anisotropy, branching, uniformity, and density in batch and microfluidic systems for optimal light-to-heat conversion upon laser irradiation. Surface-enhanced Raman scattering spectra and mesoscale temperature measurements were combined with spatially correlated scanning electron microscopy to monitor nanostar and ligand stability and microbubble formation at different laser fluences. The capability of the platform for generating controlled localized heating was used to explore hyperthermia-assisted detachment of adherent glioblastoma cells (U87-GFP) grafted to the capillary walls. Both flow and laser fluence can be tuned to induce different biological responses, such as ablation, cell deformation, release of intracellular components, and the removal of intact cells. Ultimately, this platform has potential applications in biological and chemical sensing, hyperthermia-mediated drug delivery, and microfluidic soft-release of grafted cells with single-cell specificity.},

note = {PMID: 33274287 

Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/cnma.201900754,

title = {Surfactant-Assisted Symmetry Breaking in Colloidal Gold Nanocrystal Growth},

author = {Guillermo González-Rubio and Leonardo Scarabelli and Andrés Guerrero-Martínez and Luis Liz-Marzán},

url = {https://aces.onlinelibrary.wiley.com/doi/abs/10.1002/cnma.201900754},

doi = {https://doi.org/10.1002/cnma.201900754},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {ChemNanoMat},

volume = {6},

number = {5},

pages = {698-707},

abstract = {Abstract Colloidal anisotropic gold nanocrystals play a central role in the field of plasmonics owing to their tunable optical activity across a wide spectral range. However, achieving sufficient optical quality for practical implementation requires advanced synthetic protocols yielding gold nanocrystals with the desired morphology and plasmonic properties. This Minireview focuses on a fundamental step during the growth of anisotropic nanocrystals, namely symmetry breaking. In connection with thermodynamic and kinetic control of nanocrystal growth, we discuss the complex interplay between the role of seed morphology and that of surfactants, shape-directing additives and reducing agents. We revisit some iconic syntheses of anisotropic gold nanoparticles, including nanorods, nanotriangles, and nanobipyramids. Finally, we analyze the use of co-surfactants as an emerging strategy to disconnect the symmetry breaking event from the anisotropic growth process, overcoming current limitations in the synthesis of anisotropic gold nanocrystals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.nanolett.9b04659,

title = {Tailored Nanoscale Plasmon-Enhanced Vibrational Electron Spectroscopy},

author = {Luiz H. G. Tizei and Vahagn Mkhitaryan and Hugo Lourenço-Martins and Leonardo Scarabelli and Kenji Watanabe and Takashi Taniguchi and Marcel Tencé and Jean-Denis Blazit and Xiaoyan Li and Alexandre Gloter and Alberto Zobelli and Franz-Philipp Schmidt and Luis Liz-Marzán and F. Javier García Abajo and Odile Stéphan and Mathieu Kociak},

url = {https://doi.org/10.1021/acs.nanolett.9b04659},

doi = {10.1021/acs.nanolett.9b04659},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Nano Letters},

volume = {20},

number = {5},

pages = {2973-2979},

abstract = {Atomic vibrations and phonons are an excellent source of information on nanomaterials that we can access through a variety of methods including Raman scattering, infrared spectroscopy, and electron energy-loss spectroscopy (EELS). In the presence of a plasmon local field, vibrations are strongly modified and, in particular, their dipolar strengths are highly enhanced, thus rendering Raman scattering and infrared spectroscopy extremely sensitive techniques. Here, we experimentally demonstrate that the interaction between a relativistic electron and vibrational modes in nanostructures is fundamentally modified in the presence of plasmons. We finely tune the energy of surface plasmons in metallic nanowires in the vicinity of hexagonal boron nitride, making it possible to monitor and disentangle both strong phonon–plasmon coupling and plasmon-driven phonon enhancement at the nanometer scale. Because of the near-field character of the electron beam–phonon interaction, optically inactive phonon modes are also observed. Besides increasing our understanding of phonon physics, our results hold great potential for investigating sensing mechanisms and chemistry in complex nanomaterials down to the molecular level.},

note = {PMID: 31967839},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.jpclett.9b03574,

title = {Formation of Hollow Gold Nanocrystals by Nanosecond Laser Irradiation},

author = {Guillermo González-Rubio and Thais Milagres Oliveira and Wiebke Albrecht and Pablo Díaz-Núñez and Juan Carlos Castro-Palacio and Alejandro Prada and Rafael I. González and Leonardo Scarabelli and Luis Bañares and Antonio Rivera and Luis Liz-Marzán and Ovidio Peña-Rodríguez and Sara Bals and Andrés Guerrero-Martínez},

url = {https://doi.org/10.1021/acs.jpclett.9b03574},

doi = {10.1021/acs.jpclett.9b03574},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {The Journal of Physical Chemistry Letters},

volume = {11},

number = {3},

pages = {670-677},

abstract = {The irradiation of spherical gold nanoparticles (AuNPs) with nanosecond laser pulses induces shape transformations yielding nanocrystals with an inner cavity. The concentration of the stabilizing surfactant, the use of moderate pulse fluences, and the size of the irradiated AuNPs determine the efficiency of the process and the nature of the void. Hollow nanocrystals are obtained when molecules from the surrounding medium (e.g., water and organic matter derived from the surfactant) are trapped during laser pulse irradiation. These experimental observations suggest the existence of a subtle balance between the heating and cooling processes experienced by the nanocrystals, which induce their expansion and subsequent recrystallization keeping exogenous matter inside. The described approach provides valuable insight into the mechanism of interaction of a pulsed nanosecond laser with AuNPs, along with interesting prospects for the development of hollow plasmonic nanoparticles with potential applications related to gas and liquid storage at the nanoscale.},

note = {PMID: 31905285},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{<LineBreak>doi:10.1073/pnas.1917125117,

title = {Acoustofluidic sonoporation for gene delivery to human hematopoietic stem and progenitor cells},

author = {Jason N. Belling and Liv K. Heidenreich and Zhenhua Tian and Alexandra M. Mendoza and Tzu-Ting Chiou and Yao Gong and Natalie Y. Chen and Thomas D. Young and Natcha Wattanatorn and Jae Hyeon Park and Leonardo Scarabelli and Naihao Chiang and Jack Takahashi and Stephen G. Young and Adam Z. Stieg and Satiro De Oliveira and Tony Jun Huang and Paul S. Weiss and Steven J. Jonas},

url = {https://www.pnas.org/doi/abs/10.1073/pnas.1917125117},

doi = {10.1073/pnas.1917125117},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Proceedings of the National Academy of Sciences},

volume = {117},

number = {20},

pages = {10976-10982},

abstract = {Commercial strategies to deliver biomolecular cargo ex vivo (e.g., electroporation, lipofection) to clinically relevant cell lines are limited by toxicity, cost, and throughput. These technical limitations have inhibited development of these technologies into streamlined clinical platforms for manufacturing gene-modified stem cells and cancer immunotherapies. Here, we demonstrate an acoustofluidic platform capable of delivering plasmids with high throughput to human T lymphocytes, peripheral blood mononuclear cells, and CD34+ hematopoietic stem and progenitor cells. Acoustofluidic-treated cells showed evidence of cytosolic DNA delivery, endocytic DNA aggregation, and nuclear membrane rupture. Collectively, these observations demonstrate the utility of this method as a research tool for gene editing applications and mechanistic studies of plasma membrane and nuclear membrane repair. Advances in gene editing are leading to new medical interventions where patients’ own cells are used for stem cell therapies and immunotherapies. One of the key limitations to translating these treatments to the clinic is the need for scalable technologies for engineering cells efficiently and safely. Toward this goal, microfluidic strategies to induce membrane pores and permeability have emerged as promising techniques to deliver biomolecular cargo into cells. As these technologies continue to mature, there is a need to achieve efficient, safe, nontoxic, fast, and economical processing of clinically relevant cell types. We demonstrate an acoustofluidic sonoporation method to deliver plasmids to immortalized and primary human cell types, based on pore formation and permeabilization of cell membranes with acoustic waves. This acoustofluidic-mediated approach achieves fast and efficient intracellular delivery of an enhanced green fluorescent protein-expressing plasmid to cells at a scalable throughput of 200,000 cells/min in a single channel. Analyses of intracellular delivery and nuclear membrane rupture revealed mechanisms underlying acoustofluidic delivery and successful gene expression. Our studies show that acoustofluidic technologies are promising platforms for gene delivery and a useful tool for investigating membrane repair.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adfm.201809071,

title = {Encapsulation of Noble Metal Nanoparticles through Seeded Emulsion Polymerization as Highly Stable Plasmonic Systems},

author = {Leonardo Scarabelli and Marius Schumacher and Dorleta Jimenez Aberasturi and Jan-Philip Merkl and Malou Henriksen-Lacey and Thais Milagres Oliveira and Marcus Janschel and Christian Schmidtke and Sara Bals and Horst Weller and Luis Liz-Marzán},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201809071},

doi = {https://doi.org/10.1002/adfm.201809071},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {Advanced Functional Materials},

volume = {29},

number = {14},

pages = {1809071},

abstract = {Abstract The implementation of plasmonic nanoparticles in vivo remains hindered by important limitations such as biocompatibility, solubility in biological fluids, and physiological stability. A general and versatile protocol is presented, based on seeded emulsion polymerization, for the controlled encapsulation of gold and silver nanoparticles. This procedure enables the encapsulation of single nanoparticles as well as nanoparticle clusters inside a protecting polymer shell. Specifically, the efficient coating of nanoparticles of both metals is demonstrated, with final dimensions ranging between 50 and 200 nm, i.e., sizes of interest for bio-applications. Such hybrid nanocomposites display extraordinary stability in high ionic strength and oxidizing environments, along with high cellular uptake, and low cytotoxicity. Overall, the prepared nanostructures are promising candidates for plasmonic applications under biologically relevant conditions.},

note = {Corresponding author},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/smll.201900982,

title = {Dark-Exciton-Mediated Fano Resonance from a Single Gold Nanostructure on Monolayer WS2 at Room Temperature},

author = {Mingsong Wang and Zilong Wu and Alex Krasnok and Tianyi Zhang and Mingzu Liu and He Liu and Leonardo Scarabelli and Jie Fang and Luis Liz-Marzán and Mauricio Terrones and Andrea Alù and Yuebing Zheng},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.201900982},

doi = {https://doi.org/10.1002/smll.201900982},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {Small},

volume = {15},

number = {31},

pages = {1900982},

abstract = {Abstract Strong spatial confinement and highly reduced dielectric screening provide monolayer transition metal dichalcogenides with strong many-body effects, thereby possessing optically forbidden excitonic states (i.e., dark excitons) at room temperature. Herein, the interaction of surface plasmons with dark excitons in hybrid systems consisting of stacked gold nanotriangles and monolayer WS2 is explored. A narrow Fano resonance is observed when the hybrid system is surrounded by water, and the narrowing of the spectral Fano linewidth is attributed to the plasmon-enhanced decay of dark K-K excitons. These results reveal that dark excitons in monolayer WS2 can strongly modify Fano resonances in hybrid plasmon–exciton systems and can be harnessed for novel optical sensors and active nanophotonic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/open.201900082,

title = {Robust Synthesis of Gold Nanotriangles and their Self-Assembly into Vertical Arrays},

author = {Piotr Szustakiewicz and Guillermo González-Rubio and Leonardo Scarabelli and Wiktor Lewandowski},

url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/open.201900082},

doi = {https://doi.org/10.1002/open.201900082},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

journal = {ChemistryOpen},

volume = {8},

number = {6},

pages = {705-711},

abstract = {Abstract We report an efficient, seed-mediated method for the synthesis of gold nanotriangles (NTs) which can be used for controlled self-assembly. The main advantage of the proposed synthetic protocol is that it relies on using stable (over the course of several days) intermediate seeds. This stability translates into increasing time efficiency of the synthesis and makes the protocol experimentally less demanding (‘fast addition’ not required, tap water can be used in the final steps) as compared to previously reported procedures, without compromising the size and shape monodispersity of the product. We demonstrate high reproducibility of the protocol in the hands of different researchers and in different laboratories. Additionally, this modified seed-mediated method can be used to produce NTs with edge lengths between ca. 45 and 150 nm. Finally, the high ‘quality’ of NTs allows the preparation of long-range ordered assemblies with vertically oriented building blocks, which makes them promising candidates for future optoelectronic technologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokeyr,

title = {Nanoelectrode-emitter spectral overlap amplifies surface enhanced electrogenerated chemiluminescence},

author = {Thomas S. Heiderscheit and Miranda J. Gallagher and Rashad Baiyasi and Sean S. E. Collins and Seyyed Ali Hosseini Jebeli and Leonardo Scarabelli and Alexander Al-Zubeidi and Charlotte Flatebo and Wei-Shun Chang and Christy F. Landes and Stephan Link},

doi = {https://doi.org/10.1063/1.5118669},

year  = {2019},

date = {2019-10-14},

urldate = {2019-10-14},

journal = {The Journal of Chemical Physics},

volume = {151},

number = {14},

issue = {October},

pages = {144712},

abstract = {Electrogenerated chemiluminescence (ECL) is a promising technique for low concentration molecular detection. To improve the detection limit, plasmonic nanoparticles have been proposed as signal boosting antennas to amplify ECL. Previous ensemble studies have hinted that spectral overlap between the nanoparticle antenna and the ECL emitter may play a role in signal enhancement. Ensemble spectroscopy, however, cannot resolve heterogeneities arising from colloidal nanoparticle size and shape distributions, leading to an incomplete picture of the impact of spectral overlap. Here, we isolate the effect of nanoparticle-emitter spectral overlap for a model ECL system, coreaction of tris(2,2′-bipyridyl)dichlororuthenium(ii) hexahydrate and tripropylamine, at the single-particle level while minimizing other factors influencing ECL intensities. We found a 10-fold enhancement of ECL among 952 gold nanoparticles. This signal enhancement is attributed exclusively to spectral overlap between the nanoparticle and the emitter. Our study provides new mechanistic insight into plasmonic enhancement of ECL, creating opportunities for low concentration ECL sensing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}