A Dopamine-Imprinted Chitosan Film/Porous ZnO NPs@Carbon Nanospheres/Macroporous Carbon for Electrochemical Sensing Dopamine

Abstract Dopamine (DA) is a nerve-transducing chemical that helps cells transmit pulses. Too high or too low concentration of DA is detrimental to human health. Therefore, finding a fast, efficient and sensitive method for detecting DA is of great significance. Here, a DA-imprinted chitosan (CS) film /ZnO nanoparticles (NPs)@carbon (C)/three-dimensional kenaf stem-derived macroporous carbon (3D-KSC) was prepared for electrochemical detection of DA. The DA-imprinted CS film/ZnO NPs @C/3D-KSC was prepared by growing zeolite imidazole framework-8 (ZIF-8) on 3D-KSC, carbonizing under N2 atmosphere, electrodepositing AA-CS on ZnO NPs@C/3D-KSC and eluting template AA molecules. The results showed that ZIF-8 derived porous ZnO NPs@C nanospheres were arranged evenly on 3D-KSC surface to form a monolayer. The diameter of nanospheres was approximately 500-600 nm, and the nanospheres were composed of ZnO NPs embedded in porous carbon. A layer of CS with DA-imprinted pores was covered on the ZnO NPs@C nanospheres, so the DA-imprinted CS film/ZnO NPs@C/3D-KSC integrated electrode exhibited better selectivity for DA detection. The linear range was 0.12 nM-152 μM, the detection limit was 0.039 nM, and the sensitivity was 757 μA mM-1 cm-2. The DA-imprinted CS film/ZnO NPs@C/3D-KSC integrated electrode also showed higher stability.