Fabrication of Chitosan‐Gold Nanoshells for γ‐Aminobutyric Acid Detection as a Surface‐enhanced Raman Scattering Substrate

Abstract

A surface‐enhanced Raman scattering (SERS) principle‐based brain‐probing optical fiber was produced to analyze changes in the concentration of γ‐aminobutyric acid (GABA). The procedure was carried out within the GABA administration concentration range of 5–30 mM for the patients who should take cranial medicines for GABA components of less than a normal range. The optical fiber, of which the surface had been reformed, was prepared by treatment with chitosan‐gold nanoshell particles, which were synthesized by using an ionic interaction. The treated fiber was subsequently combined with GABA, for the purpose of analyzing its GABA concentration. The calibration curve of the SERS sensitivity (counts) as determined by the concentration levels of GABA adsorbed onto the chitosan‐gold nanoshell without attachment to the optical fiber was as follows: y = 0.2x 2 − 0.6743x + 419.8 ( R 2  = 0.9874), while the corresponding calibration curve of the SERS sensitivity (counts) with attachment to optical fiber was as follows: y = 7.4057x 2 + 93.68x + 1851.4 ( R 2  = 0.9472). Based on the aforementioned two sets of data, it was confirmed that the analysis of GABA using optical fiber had a higher level of sensitivity compared to its analysis in the absence of optical fiber.