A Paper-Supported Photoelectrochemical Sensing Platform Based on Surface Plasmon Resonance Enhancement for Real-Time H 2 S Determination

Based on in situ generation of CdS quantum dots (QDs) and surface plasmon resonance (SPR) enhancement between CdS QDs and Ag nanoparticles (NPs), an innovative paper-supported photoelectrochemical (PEC) sensing platform was constructed for real-time intracellular H2S detection. SiO2 shell was coated on the Ag NPs to improve the stability of Ag NPs. H2S was used to trigger the formation of CdS QDs, thereby inducing an improvement of photocurrent response. CdS QDs grown on the Ag@SiO2 core–shell NPs worked efficiently to absorb visible light. The resulting CdS QDs–Ag@SiO2 core–shell NPs exhibit improved PEC behavior, which was attributed to the surface plasmon-resonance effect of Ag NPs. Meanwhile, the separation of cell binding from the photoelectrode would eliminate the commonly existing affection during the biorecognition processes. This novel SPR-enhanced PEC sensing platform not only achieved satisfactory analysis results toward H2S, but also showed excellent sensitivity, selectivity, low cost, and portable features. The strategy of the SPR through the in situ generation of semiconductor nanoparticles on the surface of noble metal semiconductor paves way for the improvements of PEC analytical performance.