Selective and sensitive photoelectrochemical aptasensor for streptomycin detection based on BiVOBr/TiC nanohybrids.

Sensitive detection of streptomycin (STR) has attracted increasing attention worldwide because of the relationship between food security and human health. In this paper, BiVOBr/TiC nanohybrids were obtained by one-pot solvent hydrothermal method. It was modified on ITO electrode, and STR aptamer was acted as the recognition element. With excellent photoelectrochemical (PEC) performance of BiVOBr/TiC nanohybrids, an "on-off-on" PEC aptasensor for STR detection was effectively developed. Compared with pure BiVOBr, the photocurrent intensity of as-prepared BiVOBr/TiC nanohybrids was about 9 times higher, which ascribed to the highly conductive of TiC, driving the photogenerated electrons transferred to the ITO electrode rapidly, so that the recombination of photogenerated electron and hole pairs was inhibited viably. Furthermore, the constructed "on-off-on" PEC aptasensor accomplished STR detection with high sensitivity, excellent specificity and distinguished repeatability in honey. The photocurrent increased with the increment of STR concentration with the linear range from1 nM to 1000 nM, and the detection limit of 0.3 nM (S/N = 3). Compared with the national standard method (SN/T 1925-2007), the as-constructed PEC sensor showed the consistent results.