Graphitic carbon nitride/magnetic chitosan composite for rapid electrochemical detection of lactose

Graphitic carbon nitride supported on magnetic chitosan (MNPs/CS/g-C3N4) was synthesised via facile route and used as an efficient support for covalent-based immobilisation of cellobiose dehydrogenase (CDH) and also as a modifier for glassy carbon electrode (GCE) in the fabrication of an electrochemical lactose sensor. Characterisation techniques, including field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray powder diffraction, and thermo-gravimetric analysis, were utilised to fully characterise the composite structure. According to the beneficial properties and electrical conductivity of g-C3N4, the MNPs/CS/g-C3N4 composite displayed excellent electrochemical performance for lactose detection with a low detection limit of 0.3 mM, a broad linear range of 0.9 e10 0 mM, a fast response time of 5 s, and considerably high sensitivity of 40.8 mA mM-1. More impor-tantly, the utility of the developed MNPs/CS/g-C3N4/CDH/GCE biosensor was verified in the quantification of lactose in dairy products, indicating its potential application for analysis of real samples.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Graphitic carbon nitride supported on magnetic chitosan was synthesized and used as a support for cellobiose dehydrogenase immobilization and as a modifier for glassy carbon electrode in the fabrication of an electrochemical lactose sensor. The composite exhibited excellent electrochemical performance and was successfully applied in lactose quantification in dairy products.