Zinc
and Molybdenum Co-Doped BiVO4 Nanoarray
for Photoelectrochemical Diethylstilbestrol Analysis Based on the
Dual-Competitive System of Manganese Hexacyanoferrate Hydrate Nanocubes
posted on 2020-03-25, 20:29authored byYanrong Qian, Jinhui Feng, Rui Xu, Dawei Fan, Yu Du, Xiang Ren, Qin Wei, Huangxian Ju
This
study proposes a competitive photoelectrochemical (PEC) immunosensor
for detecting diethylstilbestrol (DES). The PEC sensing platform uses
a zinc and molybdenum codoped BiVO4 nanoarray ((Zn,Mo):BiVO4) as the photoactive matrix and manganese hexacyanoferrate
hydrate loading silicon dioxide layer composite nanocubes (MHCF@SiO2 NCs) as the signal quencher. The (Zn,Mo):BiVO4 nanoarray demonstrated brilliant PEC behavior, by virtue of the
local electric field formed by the codoped Zn and Mo. This doping
accelerated the electron transfer and improved the photoelectric conversion
efficiency in BiVO4 nanoarray under visible light. Furthermore,
the nanoarray structure with its large surface area provided abundant
binding sites for the immune response. As the MHCF@SiO2 NCs-anti-DES competitively bonded with either free DES or bovine
serum albumin conjugated DES (BSA-DES), hydrogen peroxide (H2O2) as electron donor was competitively consumed and meanwhile
steric resistance blocked electrons transfer. For the above reasons,
the photocurrent signal was reduced. Thus, the standard sample free
DES was accurately detected, and the fabricated PEC immunosensor displayed
an outstanding photocurrent response from 0.1 pg/mL to 50 ng/mL with
a detection limit of 0.05 pg/mL. Simultaneously, the acceptable stability,
selectivity, and reproducibility of the designed dual-competitive
sensing platform suggest its applicability to small molecule detection.