Highly sensitive photoelectrochemical sensor for carbohydrate antigen 19-9 detection based on cauliflower heterostructure of NiS@Ni3S2/RGO/CdS composite

Abstract

The Photoactive materials with typical heterostructure and multi component have been proved that significant photoelectrochemical (PEC) performance. Herein, both microspheric NiS@Ni₃S₂/RGO/CdS(1 ∼ 2) heterojunction composites were synthesized through the solvothermal and oil-bath reflux method using Ni(btc) as MOFs precursor. Under illumination, PEC experiments showed the structured materials with superior photocurrent response than the NiS@Ni₃S₂ and CdS(1). It was ascribe to facts that the formed p-n type heterostructure between NiS and CdS markedly accelerating the transfer of charge carriers, every component in NiS@Ni₃S₂/RGO/CdS(1 ∼ 2) with well-synergistic effect was beneficial to improve the co-catalytic activities on the heterogeneous interface and relatively enhanced the photoelectric conversion efficiency. Besides, RGO as high electrical conductor could promote photo-generated electrons transport. Based on the outstanding photoelectric property of NiS@Ni₃S₂/RGO/CdS(1) to fabricate the PEC sensing platform (BSA/Ab/GLA-CS/NiS@Ni₃S₂/RGO/CdS(1)/ITO) displaying highly analysis sensitivity for carbohydrate antigen 19-9 (CA19-9), the wider linear range (0.001 ∼ 54 U⋅mL⁻¹) and low detection limit (0.41 mU⋅mL⁻¹) were achieved. The proposed PEC biosensor also had good selectivity and satisfying stability. This elaborately design of p-n heterostructure with multi-components should be great prospective for the photocatalysis or constructing the other PEC biosensor.