Rapid and sensitive detection of prohibited diuretics using silver nanostar-enhanced SERS

Certain diuretics have been identified as potential contaminants in pharmaceutical and food products, posing a risk to food safety and public health. In this study, a surface-enhanced Raman spectroscopy (SERS) detection method based on Silver nanostars (Ag NSs) was developed for the detection of motion-prohibited diuretics in food and biological samples. Ag NSs synthesized via a simple solution-based method exhibited a star-like morphology with high-density "hot spot", achieving an enhancement factor of 1.0 × 10 5 —3 orders of magnitude higher than that of traditional spherical silver nanoparticles. A highly sensitive SERS detection system was established for bumetanide (limit of detection: 7.08 × 10 −9 g/mL), triamterene (1.13 × 10⁻⁸ g/mL), and dorzolamide (1.04 × 10⁻⁸ g/mL) for the first time. Characteristic fingerprint peaks enabled accurate molecular identification. The method was validated in milk and urine with recoveries of 94.2 %–104.9 %, and relative standard deviation (RSD) < 7 %. Results were consistent with those obtained by HPLC-HRMS/MS, confirming the method's reliability. The proposed system offers advantages of rapid detection (<10 min), low cost, and minimal matrix interference, enabling efficient multi-residue analysis in complex samples. This work provides a promising tool for food safety monitoring and anti-doping surveillance, contributing to effective regulatory enforcement.