Sensitive photoelectrochemical immunosensor for squamous cell carcinoma antigen based on MoSe2 nanosheets and hollow gold nanospheres.

Graphical abstract Highlights • DITAPIBr ionic liquid controllably synthesize ultrathin MoSe 2 nanosheets. • DIBPIBr ionic liquid controllably prepare hollow gold nanospheres (HGNs). • Novel photoelectrochemical immunosensor based HGNs-MoSe 2 was fabricated. • Photoelectrochemical sensing of SCCA was fulfilled. • SCCA concentrations in clinical serum samples were accurately assayed. Abstract A photoelectrochemical immunosensor was fabricated for squamous cell carcinoma antigen (SCCA) assay with high performances by using MoSe 2 nanosheets and hollow gold nanospheres as photosensitive materials. MoSe 2 nanosheets were simply synthesized with a hydrothermal method using 1,3-di-(3-thioacetylpropyl)-imidazolium bromide (DITAPIBr) ionic liquid as a morphological controlling reagent, selenium powder, and sodium molybdate as raw materials. Hollow gold nanospheres (HGNs) were prepared by using 1,3-di-(3-bromopropyl)-imidazolium bromide ionic liquid (DIBPIBr) as functional monomer, and NaBH 4 as a reductant to interact with the HAuCl 4 solution. Subsequently, HGNs were integrated with MoSe 2 nanosheets to provide a HGNs-MoSe 2 nanocomposite. The photocurrent intensity of MoSe 2 nanosheets was significantly enhanced by the hybridization of HGNs. Furthermore, HGNs-MoSe 2 nanocomposites were coated onto a glassy carbon electrode surface to construct a platform for the immobilization of SCCA antibody (anti-SCCA), resulted in a photoelectrochemical immunosensing system for determining SCCA. Under optimized conditions, the fabricated immunosensor shows high selectivity and sensitivity towards SCCA, and exhibits a detection limit of 0.21 pg mL−1 and a linear range from 1.0 pg mL−1 to 50 ng mL−1. Meanwhile, the practicability of the immunosensor was demonstrated by determining SCCA in clinical serum samples with high accuracy. [ABSTRACT FROM AUTHOR]