Molecularly imprinted SERS sensor on paper for benzoic acid detection in rice vinegar

The excessive use of benzoic acid as a preservative in vinegar may pose health risks, highlighting the need for efficient monitoring methods. Conventional detection techniques are often costly, time intensive, and require complex sample preparation. Herein, a surface-enhanced Raman scattering (SERS) sensor on paper incorporating molecularly imprinted polymers (MIPs) was developed to enable rapid, sensitive, and selective detection of benzoic acid in rice vinegar. The sensor material (BA-MIPs@AgNPs) was synthesized via sodium borohydride reduction of silver nitrate, and its morphology and structural integrity were confirmed through electron microscopy and infrared spectroscopy, respectively. Comprehensive dynamic, static, selective, and anti-interference adsorption experiments were performed to assess the sensor's binding performance and reliability. Under the optimized parameters, the MIP-SERS sensor exhibited a strong linear response for benzoic acid concentrations between 500-2500 mg/L, with a detection limit of 250 mg/L. The recovery rates for spiked samples ranged from 95.17 % to 102.32 %, indicating high accuracy. Statistical comparison via an independent sample t test revealed no significant difference between the results obtained via the MIP-SERS method and those obtained via standard HPLC, confirming its reproducibility and analytical precision. This work presents a cost-effective, environmentally conscious approach for food safety monitoring and quality assurance practices.