BIOSSENSORES PLASM??NICOS BASEADOS EM ESPALHAMENTO RAMAN INTENSIFICADO POR SUPERF??CIE UTILIZANDO NANOBAST??ES DE OURO

摘要

There is still a significant need for low cost, fast and trustworthy diagnostic devices based on biosensors, which may impact positively for applications in developing countries. Localized surface plasmon resonance (LSPR) based biosensors have been taken as powerful alternative to deal with the above limitations. The local electromagnetic field enhancement caused by the LSPR in metallic nanomaterials allows the emergence of the surface enhanced Raman scattering (SERS) effect, which have recently been applied as biosensing platforms. In the present report, gold nanorods (AuNRs) were synthesized and modified with a sandwich immunoassay to detect bovine serum albumin antibody (anti-BSA). The sensitivity of the platform was evaluated by the extrinsic SERS signal from AuNRs in solution phase with added Nile blue as reporter molecule (AN-S-AuNRs), which was subsequently modified with bovine serum albumin (BSA); the assay consisted on capturing BSA modified AN-S-AuNRs by anti-BSA molecules immobilized on AuNRs on glass slides (AuNRs-chip). SERS mapping evidenced the analyte detection based on the substantial increase in the positive events with SERS signal of the reporter molecule in the presence of anti-BSA compared to the assay in the absence of the antibody. The present study may potentially guide the construction of efficient SERS immunosensors.