A novel photoelectrochemical singal amplification assay for procalcitonin detection based on ZnxBi2S3+x sensitized NiTiO3 matrix

An original signal amplification photoelectrochemical (PEC) immunosensor for procalcitonin detection was fabricated based on Zn x Bi 2 S 3+x sensitized NiTiO 3 nanorods. Using ethylene glycol as medium, the NiTiO 3 nanorods were successfully manufactured after calcination in air atmosphere, the rod-like structure have rough surface that produced benefit to capture lots of functional Zn x Bi 2 S 3+x , the sensitizer sensitized NiTiO 3 on ITO substrate by means of a sequential ionic layer adsorption reaction, and the obtained Zn x Bi 2 S 3+x /NiTiO 3 composites showed an excellent absorption of visible light owing to the matched band gap. By the way, Zn x Bi 2 S 3+x /NiTiO 3 composites as mimic enzyme of glucose oxidase, high sensitivity was achieved due to the generated H 2 O 2 as holes scavenger when glucose added, that promote the photo electrons transfer quickly, further increased the PEC signal. The as prepared sensor showed a large linear range of 0.0001–50 ng·mL −1 with 0.04 pg·mL −1 detection limit. Simultaneously, the signal amplification strategy of this sensor provides applicable to other PEC immunosensors for detection of other targets.