Grigory Arzumanyan
Surface-enhanced Raman scattering (SERS) is a technique developed to detect extremely small quantities of molecules by determining their characteristic Raman signal. However, the adoption of SERS remains limited due to the difficulties in fabrication of highly sensitive and reproducible nanostructured plasmonic platforms. From this point-of-view, self-assembly techniques of SERS substrates formation allowing fabrication of highly branched dendritic silver nanostructures, to our opinion, are very promising for highly sensitive biosensor applications. We also used so-called Ag corrosive deposition on a macroporous silicon (macro-PSi) template to grow 3D silver dendritic structure that demonstrated an unprecedented sensitivity in SERS spectroscopy. With the use of such substrates, it was possible for the first time to detect 4-MBA and DTNB molecules with very low concentrations of 10-16 M and 10-18 M, respectively. Besides, we examined SERS spectra of the human lactoferrin molecules adsorbed on a silvered porous silicon (P-Si) from 10-6–10-18 M solutions. To prevent overheating the analyte molecules on the silvered por-Si were protected with graphene, which allowed the detection of lactoferrin adsorbed from the 10-18 M solution. Thus, the SERS measurement results indicate the possibility of ultra-low analyte concentration detection, comparable to the concentrations of single molecules.
