Ultrasensitive photoelectrochemical sensor of oxytetracycline based on nano Au decorated nitrogen-deficient boron-doped carbon nitride nanosheets

As one of the emerging organic pollutants, oxytetracycline (OTC) has been used widely and presents a potential hazard risk to ecology and health. To achieve an ultrasensitive OTC detection, an effective photoelectrochemical (PEC) aptasensor based on nano Au decorated nitrogen-deficient boron-doped carbon nitride (Au/BCN) nanocomposites was developed. The initial carbon nitride was shortened band gap to improve light absorption to obtain the efficient photoactive BCN. Nano Au was decorated in BCN to further enhance light absorption because of its unique surface plasmon resonance effect, which favors improved detectability of the aptasensor. Meanwhile, nano Au acted as a bridge between BCN with aptamer to fix the aptamers via thiol-gold bonding. Under the influence of the holes oxidation mechanism, a wide linear range of 0.1-200 nM of OTC and a low detection limit of 0.05 nM was offered. The detection accuracy and feasibility of the proposed sensor indicated that the PEC aptasensor is a promising analytical method.