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

A photoelectrochemical immunosensor was fabricated for squamous cell carcinoma antigen (SCCA) assay with high performances by using MoSe2 nanosheets and hollow gold nanospheres as photosensitive materials. MoSe2 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 NaBH4 as a reductant to interact with the HAuC1(4 )solution. Subsequently, HGNs were integrated with MoSe 2 nanosheets to provide a HGNs-MoSe(2 )nanocomposite. The photocurrent intensity of MoSe2 nanosheets was significantly enhanced by the hybridization of HGNs. Furthermore, HGNs-MoSe2 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.