Anchoring black phosphorus quantum dots over carboxylated multiwalled carbon nanotubes: A stable 0D/1D nanohybrid with high sensing performance to Ochratoxin a

Exploration of an efficient ochratoxin A (OTA) screening technique is highly important because of its highly toxic effect on human health. Electrochemical sensor, characterized with high accuracy and precise, is an emerging detection technique for toxic agents in food samples. However, the inherent fouling effect and low electrochemical activity from OTA molecular hinder its practical application in OTA detection. Herein, we prepared a novel 0D/1D nanohybrid by anchoring black phosphorus quantum dots (BPQDs) over carboxylated multiwalled carbon nanotubes (CNTs-COOH) via a facile sonication assisted assembly approach. Characterization techniques together with theoretical approximations reveal that BPQDs can anchor onto the CNTs-COOH via strong covalent reaction, endowing the nanohybrid with high conductivity, high stability and high anti-fouling property. The electrochemical sensor constructed with the 0D/1D nanohybrid shows high electrochemical activity and a good antifouling effect in OTA detection. In optimized conditions, the sensor provide a quantitative determination of OTA in a wide concentration range from 0.4 to 10 μM with a detection limit of 0.03 μM. Moreover, the sensor shows high reproductivity and satisfactory anti-interference ability. Satisfactory recoveries that can comparable to those of high-performance liquid chromatography indicate that the sensor is promising for the trace-level analysis of OTA in agricultural crops.