A novel molecularly imprinted sensors using chitosan on nitrogen-doped hollow carbon nanospheres for bisphenol A...

It is of great significance to establish highly sensitive and reliable detection methods for bisphenol A (BPA) due to its potential health and environmental risks. In this paper, a new type of molecularly imprinted composite sphere was synthesized using nitrogen-doped hollow carbon spheres (N-HCS) as the substrate and chitosan (CS) as the imprinting material. The selective binding ability of this material to BPA and its mechanism were systematically studied. On this basis, a sensor based on this material was constructed, and its electrochemical detection performance for BPA was deeply studied. The strong non-covalent bonds between the N-HCS and CS functional groups, as well as the interactions between the CS (-OH, -NH₂) and BPA functional groups, enhance the sensitivity of the composite materials. The sensor has a wide linear range (0.005-100 μM), a low detection limit (0.28 nM), good anti-interference performance and excellent stability. The sensitivity and reliability of the sensor are superior to those of HPLC. The standard recovery rate of BPA in real samples (milk beer) was 98.0 % - 105.2 %, and the relative standard deviation (RSD) was 3.45 % - 5.69 %.