Multigram-Scale Production of Hybrid Au-Si Nanomaterial by Laser Ablation in Liquid (LAL) for Temperature-Feedback Optical Nanosensing, Light-to-Heat Conversion, and Anticounterfeit Labeling

Abstract

Recent progress in hybrid optical nanomaterials composed of dissimilar constituents permitted an improvement in the performance and functionality of novel devices developed for optoelectronics, catalysis, medical diagnostics, and sensing. However, the rational combination of contrasting materials such as noble metals and semiconductors within individual hybrid nanostructures via a ready-to-use and lithography-free fabrication approach is still a challenge. Here, we report on a two-step synthesis of hybrid Au-Si microspheres generated by laser ablation of silicon in isopropanol followed by laser irradiation of the produced Si nanoparticles in the presence of HAuCl 4 . Thermal reduction of [AuCl 4 ] − species to a metallic gold phase, along with its subsequent mixing with silicon under laser irradiation, creates a nanostructured material with a unique composition and morphology, as revealed by electron microscopy, tomography, and elemental analysis. A combination of basic plasmonic and nanophotonic materials such as gold and silicon within a single microsphere allows for efficient light-to-heat conversion, as well as single-particle SERS sensing with temperature-feedback modality and expanded functionality. Moreover, the characteristic Raman signal and hot-electron-induced nonlinear photoluminescence coexisting within the novel Au-Si hybrids, as well as the commonly criticized randomness of the nanomaterials prepared by laser ablation in liquid, were proved to be useful for the realization of anticounterfeiting labels based on a physically unclonable function approach.

Single-Step Fabrication of Resonant Silicon–Gold Hybrid Nanoparticles for Efficient Optical Heating and Nanothermometry in Cells

“…12 For instance, Mie-resonant NPs localize electromagnetic energy within the NP material, which results in a highly enhanced light−matter interaction and temperature-dependent Raman response. 13 In turn, localized surface plasmon resonance in plasmonic NPs can provide efficient heating, which results in increased absorption of electromagnetic energy and its further conversion into localized heat. 14 Thus, a combination of key advantages of dielectric and plasmonic NPs in hybrid NPs enables the creation of nanomaterials with outstanding optical performance for simultaneous optical heating and nanothermometry.…”

Gas Sensing of Laser-Produced Hybrid TiO2-ZnO Nanomaterials under Room-Temperature Conditions

“…Pulsed laser ablation in liquid (PLAL) is a simple, easy-to-use, and convenient method to generate diverse nanomaterials at a laboratory scale [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. It is an environmentally friendly approach that has become increasingly popular over the last 2–3 decades for its ability to produce metallic, metal oxide, sulfide, and carbide nanoparticles (NPs), among others, with “clean” surface and controlled sizes, chemical composition, and morphology [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Typically, a laser beam is focused on a solid target that is immersed in a liquid medium, resulting in plasma, vapor, or molten metal drops ejected into the liquid phase.…”

“…Typically, a laser beam is focused on a solid target that is immersed in a liquid medium, resulting in plasma, vapor, or molten metal drops ejected into the liquid phase. After further quenching and/or reaction with the liquid, such species form nuclei and clusters that then grow as NPs whose morphology, size, and chemical composition depend on the laser pulses, target, and liquid used [ 1 , 3 , 4 , 5 , 6 , 7 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. When noble metals are ablated, pure metal NPs are generated [ 4 , 6 ], while the ablation of more reactive metals in water or organic solvents leads to the production of metal oxide NPs [ 4 , 6 , 7 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…When noble metals are ablated, pure metal NPs are generated [ 4 , 6 ], while the ablation of more reactive metals in water or organic solvents leads to the production of metal oxide NPs [ 4 , 6 , 7 , 10 , 11 , 12 , 13 , 14 , 15 ]. Because of extremely high-temperature gradient and quenching rates created in the ablation zone during PLAL, nanomaterials rich in defects, with metastable phases or unique morphologies are often formed [ 3 , 4 , 5 , 6 , 7 ]. This explains why such nanomaterials are potentially attractive for catalysis, photocatalysis, optics, and optoelectronics, as well as for gas sensing applications [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ].…”

“…Because of extremely high-temperature gradient and quenching rates created in the ablation zone during PLAL, nanomaterials rich in defects, with metastable phases or unique morphologies are often formed [ 3 , 4 , 5 , 6 , 7 ]. This explains why such nanomaterials are potentially attractive for catalysis, photocatalysis, optics, and optoelectronics, as well as for gas sensing applications [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ].…”