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1Au/Ag-functionalized silicon nanostructures: a comprehensive study of SERS efficiency for rapid detection and analysis of chemicals, biomolecules and bio-objects
L.A. Osminkina1*
1-Lomonosov Moscow State University, Faculty of Physics, Leninskie gory 1, 119991, Moscow, Russia
Development of highly sensitive nano-biosensors for rapid detection and analysis of chemicals, biomolecules, and bio-objects is a crucial task in laser technology. A serious breakthrough in the field of biosensorics is now expected from the application of the optical non-invasive method of Surface-Enhanced Raman Scattering (SERS) for these purposes, as it is characterized by high sensitivity, specificity and rapid response. The SERS method consists in amplifying the intensity (in billions of times) of the optical Raman signal from the molecules of the analyzed substance using special SERS-active substrates containing noble metal particles (usually gold, silver, copper) to register the signal. The sensitivity of the method directly depends on the morphological features of the substrates used: not only the shape and size of metal particles, but also their location in the solid-state matrix - the base of the sensor layer - is of great importance.
Our investigation delves into the intricate details of Au/Ag-functionalized silicon nanostructures, considering factors such as morphology, composition, and arrangement. These factors play a crucial role in enhancing the SERS efficiency of the nanostructures. Through a comprehensive study, we seek to optimize their performance for a wide range of applications, including label-free determination of biomolecules [1], metabolites [2], virus and bacteria [3] diagnostics (Fig.1), and rapid bacteria antibiotic
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Raman shift, cm-1
Figure 1. (a) SEM microphotograph of AuAg@pSiNWs after incubation with L. innocua. (b) Raman and SERS spectra of L. innocua absorbed on pSiNW and AuAg@pSiNW substrates, respectively. [3]
Ultimately, our work highlights the promising applications of Au/Ag-functionalized silicon-based nanostructures in the development of laser technologies for biomedical diagnostics. By combining the advantages of using nanotechnology and advanced laser technologies for biosensing, we aim to contribute to the development of innovative solutions for the rapid and accurate detection of pathogens and biomolecules, which will ultimately benefit public health.
The study was supported by the Russian Science Foundation grant No. 22-72-10062, https://rscf.ru/project/22-72-10062/
[1] A.D. Kartashova, et al, Surface-enhanced Raman scattering-active gold-decorated silicon nanowire substrates for label-free detection of bilirubin, ACS Biomaterials Science & Engineering, 2021. vol. 8. №. 10. pp. 4175-4184.
[2] O. Zukovskaja, et al, Rapid detection of the bacterial biomarker pyocyanin in artificial sputum using a SERS-active silicon nanowire matrix covered by bimetallic noble metal nanoparticles, Talanta, 2019. vol. 202. pp. 171-177.
[3] D.A. Nazarovskaia, et al, Advanced Bacterial Detection with SERS-Active Gold-and Silver-Coated Porous Silicon Nanowires, Bulletin of the Russian Academy of Sciences: Physics, 2023. vol. 87. №. Suppl 1. pp. S41-S46.
sensitivity analysis.
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