Boosting ultrasensitive electroanalytical detection of antibiotics at triphasic interface enzymatic biosensor

Abstract

Electroanalytical procedures are often closely bound up the gas molecules. However, the detection limitation of some electroanalytical procedures was largely limited by the lower solubility of gas molecules in liquid. To address this problem, a photoelectrochemical enzymatic biosensor with triphasic interface was designed for antibiotics detection. The hydrophobic porous carbon paper (CP) with atomic layer deposition (ALD) Zinc oxide (ZnO) film and Tungsten disulfide (WS₂) sheets were used for fixing laccase (Lac) to form Lac/WS₂/ZnO/CP, which contacted with analyst solution on one side and exposed to the gas phase directly on the other. Impressively, the catalytic activity of Lac on WS₂/ZnO/CP was promoted by adjusting the oxygen concentration from the gas phase and generated significant electrochemical response for sensitively detecting tetracycline (TC), resulting in minimum detection limit of 1.81 fM in the range of 10–200 μM. Additionally, the recovery rate of environmental samples remained at 96.07 %–104.48 %, confirming the reliability and practicality of the prepared biosensors. This strategy provided a potential method to upgrade the optical properties and enzyme activities of biosensor with eventual applications in bioanalysis.