A highly sensitive electrochemical sensor for the detection of chloramphenicol based on Ni/Co bimetallic metal-organic frameworks/ reduced graphene oxide composites

A highly and simply sensitive electrochemical sensor has been developed for the detection of trace chloramphenicol (CAP) in water based on Ni/Co bimetallic metal-organic frameworks -reduced graphene oxide composites [rGO/NiCo-BTC MOFs (BTC = 1,3,5-benzenetricarboxylicacid)] modified glassy carbon electrode (GCE/ rGO/NiCo-BTC MOFs). The bare glassy carbon electrode was initially coated with graphene oxide (GO). Subsequently, the GO was electrochemically reduced to obtain reduced graphene oxide (rGO). NiCo-BTC MOFs was grown on the surface of rGO modified electrode by in -situ electrochemical synthesis method to construct GCE/ rGO/NiCo-BTC MOFs. The as -made composites films have been characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy -dispersive X-ray, high -resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Further, different electrochemical techniques were utilized for investigating the electrochemical reduction behaviors of CAP at GCE/rGO/NiCo-BTC MOFs. This composites film modified electrode combines the large surface area and excellent electrical properties of rGO with the good catalytic activity of NiCo-BTC MOFs, resulting in a significant enhancement of the electrochemical signal during the electroreduction of CAP. Under the optimized experimental conditions, the sensor exhibits excellent sensing performance for CAP, with a wider linear dynamic range (0.1 - 100 mu M), a lower limit of detection (0.235 mu M) (S/N = 3) and a ultra -high sensitivity (33.12 mu A.mu M -1 . cm -2 ). The tap water spiked with different concentrations of CAP were considered. The recoveries range from 97.79 % to 100.07 %, with relative standard deviations ranging from 3.45 % to 5.40 %. The method has been successfully applied for the determination of CAP in real samples, yielding satisfactory results. With further research and development, electrochemical in -situ synthesis of MOFs composites have the potential to revolutionize the design and performance of electrochemical sensors, holding great promise in the field of electrochemical sensing.