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Registration Number

0224U033241, (0124U002059) , R & D reports

Title

Development of a technique for detecting explosive materials based on the methods of SERS spectroscopy and localized surface plasmon resonance

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Виготовлення та комплексна характеризація ППРС-підкладок та МІП-підкладок, з наноструктурованою морфологією поверхні, шляхом формування на гладкій підкладці скла чи кремнію саморганізованих шарів наносфер діоксиду кремнію. Напилення тонких шарів золота/срібла на дані підкладки. Аналіз ППРС та ЛППР спектрів вибухонебезпечних речовин, нанесених на дані підкладки

Head

Mazur Nazar V., Доктор філософії

Registration Date

23-12-2024

Organization

V. Lashkaryov Institute of Semiconductor Physics of National Academy

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The purpose of the research work is to develop a technique for detecting low concentrations of explosive substances using two complementary optical methods - localized surface plasmon resonance (LSPR) and surface-enhanced Raman spectroscopy (SERS). Both methods are based on the phenomenon of plasmon resonance, but they provide different information about the analytes. The LSPR method allows very accurate determination of the amount of adsorbed analyte, even if it is present in very small amounts. Raman spectroscopy, on the other hand, can determine the type of compound or even identify a specific molecule, but it is less effective for quantitative analysis of substances. That is why the combination of SERS and LSPR techniques will increase the credibility and reliability of the results of detecting explosive substances.

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 During the reporting period, a series of SERS substrates with nanostructured surface morphology was manufactured by forming self-organized layers of SiO2 nanospheres, which were formed on a Si substrate, by drop-casting and subsequent thermal deposition of a silver layer (15 nm) and annealing in an Ar atmosphere at temperatures of 200-500˚С. The morphology of these substrates was studied using scanning electron spectroscopy. Optical reflection spectra were also measured, which showed the presence of localized surface plasmon resonance bands at 420-425 nm. The following analogues of explosive substances were studied on these substrates: 4-nitrophenol, 4-nitrotoluene, 1-nitronaphthalene, 5-nitroisoquinoline, picric acid. The analyte molecules under study were drop-casted onto the obtained SERS substrates and Raman light scattering spectra were measured, with the excitation laser wavelength of 457 nm (which is resonant with the LPPR). Raman spectroscopy was used to record the spectra of the studied samples with low concentrations (from 10^-4 to 10^-7 M for different samples). For all the analytes under study, the Raman light scattering enhancement coefficients were calculated, which ranged from 10^2 to 10^6. A series of substrates consisting of arrays of gold (and silver) nanoparticles was also manufactured, with the subsequent creation of a MIP (molecularly implanted polymer) layer using the photochemical polymerization method with templates for the corresponding molecules. The extinction spectra of MIP substrates were measured, as well as the surface morphology using atomic force microscopy. The SERS studies of signals from analogues of explosive substances deposited on the corresponding substrates were carried out. Using SERS, spectra with a concentration of up to 10^-5M were recorded. The spectra of molecules that do not correspond to their template on the substrate were not registered, which indicates the selectivity of the substrate.

Product Description

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Isaieva Oksana F.
Demydov Petro V.
Lytvyn Vitalii K.

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2024-12-23