Detection of Paracetamol in Water and Urea in Artificial Urine with Gold Nanoparticle@AI Foil Cost-efficient SERS Substrate

Abstract

A cost‑efficient and easily prepared SERS substrate—gold nanoparticles (AuNPs) on untreated aluminum foil (AlF)—was demonstrated to effectively detect paracetamol in water and urea in artificial urine. The limit of detection (LOD) for paracetamol was improved to 0.1 mM (vs. 1 mM in literature). For urea detection, the substrate showed better concentration range, linearity, and LOD than AuNPs on glass, and matched performance of AuNPs on Au film with a superior semi‑logarithmic trendline (R² = 0.98 vs. 0.94). The urea LOD was 0.024 M, with a LOQ of 0.026 M, suitable for detecting physiological and pathophysiological urine concentrations (0.03–0.15 M).