Ultrathin-layered carbon intercalated MoS2 hollow nanospheres integrated with gold nanoparticles for photoelectrochemical immunosensing of squamous cell carcinoma antigen

Abstract

Abstract Ultrathin-layered carbon intercalated MoS2 hollow nanospheres (C/MoS2) were prepared with a hydrothermal method combined with high-temperature annealing using cetyltrimethylammonium bromide (CTAB) as the morphological control agent and ammonium molybdate as the molybdenum source. The ultrathin-layered C/MoS2, possessing a direct band-gap of ˜1.8 eV, can promote the visible light absorption and the charge-hole separation ideal for photoelectrochemical (PEC) sensing. Then, the gold nanoparticles (AuNPs) were integrated onto the C/MoS2 surface by in-situ reduction of chloroauric acid without adding any reductant to produce AuNPs/C/MoS2 nanocomposites. Subsequently, AuNPs/C/MoS2 nanocomposites and SCCA antibody (anti-SCCA) were sequentially modified on a glassy carbon electrode (GCE) surface to prepare a PEC immunosensing platform which was denoted as anti-SCCA(BSA)/AuNPs/C/MoS2/GCE. Under optimized conditions, the PEC immunosensor shows a broad linear range from 0.005\u202fng\u202fmL−1 to 8\u202fng\u202fmL−1 and a low detection limit of 1.8\u202fpg\u202fmL−1 for determining SCCA. For the assay of SCCA in clinical serum samples, the results obtained from the PEC immunosensor are comparable to the generally accepted ELISA method from a commercial immunoassay kit.