<p>Wearable sensors represent a promising platform for the non-invasive and continuous monitoring of biomarkers in biological fluids, showing considerable potential for real-time health management. In this study, we designed a wearable device integrated with gold nanoparticles (AuNPs) for glucose detection. The system features in-situ synthesized AuNPs embedded in a polyacrylamide (PAM) hydrogel—denoted as AuNPs@PAM—enabling dual-mode readout through both visual observation and UV–visible spectrophotometry. By leveraging the dual peroxidase-like and glucose oxidase-like activities of AuNPs, a nanozyme-enzyme cascade catalytic system was constructed for colorimetric glucose sensing, which demonstrated high sensitivity and strong stability. The in-situ synthesis of AuNPs within the PAM matrix enhances nanoparticle stability and increases the reactive surface area, thereby improving catalytic efficiency. Owing to the high flexibility and optical transparency of the PAM hydrogel, the sensing patch enables rapid and reliable glucose detection by both instrumental and visual means. Consequently, a sensitive and visually responsive flexible sensor has been successfully fabricated, offering an effective tool for non-invasive biomarker monitoring in superficial biofluids.</p>