A photoelectrochemical sensor for hydrogen sulfide in cancer cells based on the covalently and in situ grafting of CdS nanoparticles onto TiO2 nanotubes

A facile photoelectrochemical sensor for the determination of hydrogen sulfide (H 2 S) is developed. Photocurrent is generated through the grafting of CdS nanoparticles covalently and in situ onto TiO 2 nanotubes . The surface of TiO 2 nanotubes was modified by a layer of thioglycolic acid (TGA) to introduce thiol groups which can adsorb and immobilize Cd ions . CdS nanoparticles would be formed onto TiO 2 nanotubes after treating with exogenous or endogenous H 2 S. Both the exogenous and H 2 S released from cancer cells were detected based on the photoelectric properties of CdS nanoparticles. And a wide linear range (10   nM–10 6   nM) was achieved with a detection limit of 0.7   nM.