Concentration Indicator Kit Based on Dandelion Propagation‐Inspired SERS Strategy

Surface-enhanced Raman scattering (SERS) technology has been extensively employed for the detection of liquid samples in the biomedical field due to high sensitivity and non-invasive characteristics. However, quantitative SERS detection is hindered by sophisticated instrumentation and complex calibration procedures, while qualitative analyses often provide insufficient concentration information for clinical diagnosis. Herein, a concentration indicator kit based on dandelion propagation-inspired SERS strategy is developed for the semi-quantitative detection of drug residues in urine. This strategy achieves significant signal enhancement through the synergistic effects of optimized hotspot construction and molecular adsorption, resulting in an analytical enhancement factor of 2.503 × 10⁵, which is 4143 times greater than that of silver nanoparticles. An innovative phenomenon termed the "concentration indicator" is discovered, wherein the SERS signal is dramatically enhanced at specific indicated concentrations while remaining weak at adjacent concentrations. The practical utility of this kit is validated through the detection of 2-mercaptobenzothiazole in urine samples. The kit exhibits excellent performance in semi-quantitative detection of standard solutions and simulated samples at high, indicated, and low concentrations. The concentration indicator opens new avenues for the development of simplified and reliable SERS-based detection, offering a promising platform for bedside testing in medical diagnostics.