Glucose Detection Using 4-mercaptophenyl boronic acid (4-MPBA)-immobilized-Surface-Exposed Nanoparticle Sheets (SENS) as a Surface-Enhanced Raman Scattering (SERS) substrate Aldo Novaznursyah Costrada, Nina Siti Aminah, Dessy Natalia, Mitra Djamal, and Steven Bell
Institut Teknologi Bandung
Queen^s University Belfast
Abstract
Glucose detection using Surface-Enhanced Raman Scattering (SERS) is currently attracting significant attention and posing challenges due to small glucose Raman scattering cross-section. In this work, SERS substrates were fabricated using a self-assembly technique involving gold nanoparticles synthesized in an oil-water phase with the aid of a promoter known as Metal Liquid-Like Films (MeLLFs). This technique produces SERS substrates known as Surface-Exposed Nanoparticle Sheets (SENS). Characterization of SENS was performed using Crystal Violet (CV) with a detection limit of up to ~10-6 M. A monolayer of 4-mercaptophenyl boronic acid (4-MPBA), as Raman probe, self-assembled on the SENS surface through covalent interactions between its thiol groups and the SENS surface. This interaction resulted in a functionalized SERS substrate for glucose detection. The specific binding of glucose at a concentration of 10 mM with the boronic acid in 4-MPBA at pH 7.4 significantly affects the Raman signal on the SERS at a Raman shift of 1562 cm-1, which is the C-C stretching vibration mode with a shoulder at 1583 cm-1. These results indicate that glucose can be detected using a SERS substrate in the form of SENS from gold nanoparticles whose surfaces are functionalized with 4-MPBA.
