Development of a highly sensitive and selective molecularly imprinted electrochemical sensor for sulfaguanidine detection in honey samples

A simple and highly sensitive approach was performed to synthesize a selective sulfaguanidine (SG) sensor based on a molecularly imprinted electropolymer of acrylamide (PAM) for honey quality control. SG was detected by measurements of electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). These techniques were applied successfully to determine SG with an excellent selectivity when compared to the results of interfering compounds. Furthermore, unprecedented, ultra-low limits of detection (LOD) and quantification (LOQ) of 0.20 pg·mL−1 and 0.67 pg·mL−1, respectively according to DPV measurements and 0.17 pg·mL−1 and 0.57 pg·mL−1 according to EIS measurements. The proposed approach is found to be inexpensive, selective and very sensitive, thanks to the good biocompatibility of SG/PAM composite. The results also showed that this sensor was successfully applied to detect SG residues in honey samples with recoveries between 83.9% and 99.7% and had the potential to be further developed for other multiple analytes detection, thus offering an emerging horizon for bio-sensing applications in honey quality control.