Sensitive sers platform of bimetallic nanoparticles immobilized on the gold grating surface

Surface-enhanced Raman spectroscopy (SERS), stemming from the gigantic light energy focusing near the plasmon-active surface, provides the possibility to reveal the presence of targeted analytes under extremely dilute conditions. At present, SERS sensors have been making significant progress regarding practical applications in the analytical and bioanalytical fields. The main delaying factors in SERS development are related to the poor signal reproducibility. Proposed work is aimed at the achievement of highly-reproducible SERS results. The high sensitivity of SERS has been achieved through the immobilization of sharp-edges bimetallic specific nanoparticles-gold/platinum nanourchins (Au@PtNPs), on the gold grating surface, through the 1,4-benzendithiol (BDT) or 4-sulfobenzenediazonium tosylate (ADT-SH). Gold grating, able to support the surface plasmon polariton (SPP) excitation and propagation, was created on the polymer substrate using the excimer laser modification with further metal deposition. Bimetallic nanoparticles, able to efficiently excite the localized surface plasmons (LSPs), were synthesized using the wet chemical approach. Immobilization of Au@PtNPs on the gold grating allows to achieve SPP-LSP coupling and significantly SERS enhancement, with the maintaining of signal reproducibility, provided by the periodical surface. More detailed experiments show that in the case of ADT-SH, the better Au@PtNPs grafting density and SERS enhancement factor were achieved. Moreover, the produced structure allows SERS measurements with a portable Raman spectrophotometer.