Fabrication of ultra-sensitive photoelectrochemical aptamer biosensor: Based on semiconductor/DNA interfacial multifunctional reconciliation via 2D-C3N4

In this work, we fabricate a novel bismuth vanadate/two dimensional-carbon nitride/deoxyribonucleic acid (BiVO 4 /2D-C 3 N 4 /DNA) aptamer photoelectrochemical (PEC) sensor, and this sensor provides a record detection sensitivity area (5 × 10 −7  μg/L - 10 μg/L) for Microcystin-LR (MC-LR). Meanwhile, except for MC-LR detection, this sensor presents highly sensitivity for tumor marker, heavy metal ion , antibiotic also by changing the DNA aptamer. Photo charge dynamic and theory calculation results reveal that 2D-C 3 N 4 is a key material for multifunctional interface reconciliation of this PEC aptamer sensor. Firstly, it can serve as photogenerated hole oriented-transfer medium from the BiVO 4 photoanode to the detective target; In addition, 2D-C 3 N 4 with large area of π electron cloud can fix the DNA aptamer parallelly by π-π bonding with the nucleic acid in the DNA aptamer to shorten the hole transfer distance from the semiconductor to target. So that, a record MC-LR detection sensitivity has been achieved by the 2D-C 3 N 4 modified BiVO 4 /DNA aptamer sensor.