Interfacial SERS Analyzer Based on Silver Nanoparticles Array for In vivo Monitoring of 5-Hydroxytryptamine in Rat Brain Microdialysates and Serum

Reliable determination of chemical expression in the brain is crucial for understanding and elucidating the molecular mechanisms underlying brain function. As a powerful analytical tool, surface-enhanced Raman scattering (SERS) has been widely employed to probe trace analytes in biological samples. However, the application of SERS for trace detection is often hindered by background interference and the influence of non-adsorptive molecules near the SERS hotspots. Herein, we developed a functionalized AgNPs-based interfacial SERS platform at the 1,2-dichloroethane/water (DCE/W) interface. This platform utilized a 5-hydroxytryptamine (5-HT) aptamer, labeled with carboxy rhodamine, as a specific Raman reporter to achieve high selectivity for 5-HT through conformational changes. Simultaneously, the AgNPs are tightly packed at the DCE/W interface to ensure a uniform distribution of hotspots, enhancing both the detection sensitivity and reproducibility of 5-HT. Combined with the microdialysis technique, this SERS platform was successfully applied for the detection of 5-HT in rat serum and cerebral microdialysates under spontaneous hypertension. (Figure presented.)