High Performance of Formaldehyde Detection Based on Fluorescent Material Carbon Quantum Dots-Cu Nanoparticles as Working Electrode

Herein, carbon quantum dots (CQDs) incorporated with Cu nanoparticles (CuNPs), abbreviated as CQDs-CuNPs, were successfully synthesized by using a facile hydrothermal treatment of an economical approach. Furthermore, the nanocomposite CQDs-CuNPs were modified mechanically with graphene becoming Gr/CQDs-CuNPs, and then used as an electrode. The optical structural properties, morphology, crystal structure, and functional group of the CQDs have been studied by using several analytical techniques such as ultraviolet—visible spectrophotometry, scanning electron microscopy, X-ray detection, and Fourier-transform infrared spectroscopy. Experimental results show that the Gr/CQDs-CuNPs electrode exhibits a sensitive electrochemical response to formaldehyde, with a linear current response to formaldehyde concentration in a wide concentration range. In addition, the Gr/CQDs-CuNPs electrode also showed significant catalytic activity towards formaldehyde reduction. This study also considers factors that influence the response of electrodes to formaldehyde, such as the pH of the electrolyte solution, the measurement rate, and the working potential. The results of this research have broad potential applications in formaldehyde detection in various fields, including environmental monitoring, food analysis, and detection of formaldehyde toxicity in consumer products. In addition, the Gr/CQDs-CuNPs electrode concept can be used as a basis for the development of more sensitive and selective electrochemical sensors for various other organic compounds.