Functionalization of nc-Si/SiO$_2$ semiconductor quantum dots by oligonucleotides

nc-Si/SiO$_2$ crystalline semiconductor quantum dots are very attractive as fluorescent labels for developing biosensors integrated with biomedical materials due to their unique physical properties in the visible region of the spectrum. We report on the functionalization of such nanostructures by single-strand short oligonucleotides using the d(20G,20T) system (d is deoxyribonucleotide, G is guanine, and T is thymine) as an example. Oligonucleotides are obtained by chemical synthesis using the solid-phase phosphoramidite technique. Studies using developed methods of Raman spectroscopy of high spectral and spatial resolution are performed on such complexes. The previously unpredicted phenomenon of multiband selective resonant light scattering by isolated molecular groups, caused by the nonradiative transfer of photoexcited electrons, is observed using a system of nc-Si/SiO2 quantum dots functionalized by d(20G,20T) oligonucleotides as an example. The results obtained suggest that the developed approach can be used to study the molecular structure of semiconductor quantum-dot and DNA complexes.