Molecularly imprinted electrochemical sensor based on AuNPs-nitrogen doped graphene-MXene nanocomposite for the detection of kanamycin in milk

Kanamycin (KANA), a broad-spectrum antibiotic, is a potential threat to the human health and environment. Therefore, it is of great significance to establish a highly sensitive and selective detection method for KANA. A novel molecularly imprinted polymers (MIPs) electrochemical sensor based on Au nanoparticles (AuNPs), nitrogen-doped graphene (NG) and MXene nanocomposite modified glassy carbon electrode (MIPs/AuNPs-MXene-NG/GCE) was developed for KANA analysis in this paper. The physicochemical performances of the nanocomposite were characterized using various techniques including SEM, TEM, XRD, XPS and electrochemsitry. The results showed that the decoration of AuNPs on MXene enhanced the conductivity and electrochemical response, the presence of MXene and NG increased the specific surface area and active sites, and the synergistic effects were favorable to the electrode performances. Under the optimal conditions, MIPs/AuNPs-MXene-NG/GCE was applied to KANA detection using differential pulse voltammetry (DPV), which achieved a wide detection range from 0.1 nmol/L to 1.0 mmol/L with a low detection limit of 0.033 nmol/L (S/N = 3). Moreover, the sensor shows excellent stability, selectivity and reproducibility, and successfully applied to the detection of KANA content in different types of milk samples with satisfactory results. The recovery was ranged from 86.0% to 113.0% with the relative standard deviation less than 4.06%. Therefore, the developed sensor provides a new idea for the efficient analysis of KANA in food samples. • A novel molecularly imprinted polymers electrochemical sensor based on Au nanoparticles, nitrogen-doped graphene and MXene nanocomposite was developed. • The molecularly imprinted electrochemical sensor exhibited excellent selectivity, stability and designability for kanamycin. • The molecularly imprinted electrochemical sensor was successfully applied to the detection of kanamycin in milk samples.