Ag-GO nanohybrid-based SERS platform for the detection of β-carotene in plant samples

Abstract

In this study, the nanohybrid of silver nanoparticles (AgNPs) and graphene oxide (GO), denoted as Ag-GO, was synthesised and investigated as a surface-enhanced Raman scattering (SERS) substrate for the detection of β-carotene in plant samples. Structural characterisation results confirmed the successful formation of the hybrid structure, with effective distribution of AgNPs on the GO surface. The Ag-GO substrate exhibited a Raman signal enhancement for β-carotene, providing an approximately 1.9 times, signal enhancement compared with AgNPs due to the synergistic effect between the electromagnetic enhancement of AgNPs and the chemical enhancement contribution of GO. Under optimised conditions, the developed SERS substrate showed good analytical performance with a linear response in the concentration range of 30-300 µM (R²=0.99), with a limit of detection (LOD) of 19.33 µM. Recovery experiments in plant samples yielded satisfactory recoveries ranging from 87.13 to 119.74% with relative standard deviations (RSDs) below 5%, demonstrating the applicability of the Ag-GO substrate for SERS-based detection of biological molecules in plant-related analysis.