Publications

The field of nanophotonics has seen remarkable advances, with gold-based materials standing out. By precisely fine-tuning the size and shape of metal nanoparticles (NPs), such as gold nanoparticles (AuNPs), it has been possible to gain control over light interaction, modulating localized surface plasmon resonance (LSPR), a phenomenon that involves the collective oscillation of free conduction electrons. This has opened the path toward more powerful biomedical applications, including surface-enhanced Raman spectroscopy (SERS) and photothermal therapy (PTT). When AuNPs dimensions fall below 2 nm, they become gold nanoclusters (AuNCs), losing the LSPR but acquitting fluorescence due to their molecule-like behavior. This unique feature makes them ideal for high-resolution imaging, biomarker detection, and advanced therapies. Beyond traditional uses, the recent inclusion of AuNPs into nanomotors (NMs) enhances precise in vivo tracking and targeted drug delivery. This review highlights the different applications of plasmonic nanomaterials with particular emphasis on AuNPs and AuNCs as a function of their shapes, sizes, and stabilization ligands. Moreover, it dives into the biosensing applications of plasmonic materials by addressing their so-called far-field and near-field optical properties, giving a detailed overview of different high-sensitivity immunoassays and biosensing. A comprehensive outlook on the evolution of plasmonic-based materials for the next therapies is provided.

JTD Keywords: Albumin-gold nanoclusters, Cancer-cells, Gold nanoparticles, Intracellular ph, Microwave-assisted synthesis, Nanoclusters, Nanomotors, Optical-properties, Plasmonic biosensors, Protein-directed synthesis, Rapid synthesi, Resonance immunoassay, Ser, Sers, Silver nanoparticles, Ultrasensitive detection

Ratiometric fluorescent nanothermometers with near-infrared emission play an important role in in vivo sensing since they can be used as intracellular thermal sensing probes with high spatial resolution and high sensitivity, to investigate cellular functions of interest in diagnosis and therapy, where current approaches are not effective. Herein, the temperature-dependent fluorescence of organic nanoparticles is designed, synthesized, and studied based on the dual emission, generated by monomer and excimer species, of the tris(2,4,6-trichlorophenyl)methyl radical (TTM) doping organic nanoparticles (TTMd-ONPs), made of optically neutral tris(2,4,6-trichlorophenyl)methane (TTM-αH), acting as a matrix. The excimer emission intensity of TTMd-ONPs decreases with increasing temperatures whereas the monomer emission is almost independent and can be used as an internal reference. TTMd-ONPs show a great temperature sensitivity (3.4% K-1 at 328 K) and a wide temperature response at ambient conditions with excellent reversibility and high colloidal stability. In addition, TTMd-ONPs are not cytotoxic and their ratiometric outputs are unaffected by changes in the environment. Individual TTMd-ONPs are able to sense temperature changes at the nano-microscale. In vivo thermometry experiments in Caenorhabditis elegans (C. elegans) worms show that TTMd-ONPs can locally monitor internal body temperature changes with spatio-temporal resolution and high sensitivity, offering multiple applications in the biological nanothermometry field.© 2023 The Authors. Small published by Wiley-VCH GmbH.

JTD Keywords: dual emission, elegans, excimer emission, fluorescence, in vivo sensing, luminescence, nanoparticles, organic radical nanoparticles, ratiometric nanothermometers, sensors, thermometry, trityl radicals, Caenorhabditis elegans, Excimer emission, In vivo sensing, Intracellular ph, Luminescence, Organic radical nanoparticles, Ratiometric nanothermometers, Trityl radicals