Visible photoelectrochemical sensing platform by in situ generated CdS quantum dots decorated branched-TiO nanorods equipped with Prussian blue electrochromic display.

In this study, based on in situ generation of CdS quantum dots (QDs) on the surface of branched TiO (B-TiO) nanorods, an solar innovative photoelectrochemical (PEC) sensing platform was constructed for real-time, and sensitive detection of cellular HS. Specifically, B-TiO nanorods arrays consisting of TiO nanorods directly grown on fluorine-doped tin oxide (FTO) further using TiCl mediated surface treatment of TiO nanorods are designed and fabricated as a new type of photoelectrode. CdS quantum dots (QDs) was formed on the surface of B-TiO nanorods arrays through the reaction between Cd and S. And a significant enhancement in the photocurrent was obtained that ascribed to the formation of CdS-B-TiO heterostructures, thus leading to sensitive PEC recording of the HS level in buffer and cellular environments. By using Prussian blue (PB) a electrochromic material to capture the photoelectron generated from the photoelectrode, a new visual system was proposed due to the formation of Prussian white (PW), which could be used to visualize the quantum photoelectric effect. This novel PEC sensing platform not only achieved satisfied analysis results toward S, but also showed excellent sensitivity, selectivity, low cost, and portable features. The strategy through the in situ generation of semiconductor nanoparticles on the surface of wide band-gap semiconductor paves the way for the improvements of PEC analytical performance. Meanwhile, the quantitative read-out electrochromic display paves a facile avenue and initiates new opportunities for creation of cheap, miniaturization sensors for other relevant analytes.