Electrochemical Sensors Based on Metal-Porous Carbon Nanozymes for Dopamine, Uric Acid and Furazolidone

A series of electrochemical sensors based on metal-porous carbon nanozymes were developed for the detection of dopamine (DA), uric acid (UA) and furazolidone (FZ). The metal-porous carbon nanozymes were prepared by calcination of porous crystalline covalent-organic frameworks (COFs) loaded metal ions. By carbonizing, the COFs was transformed into carbon nanosheets (CN) and metal ions were reduced into 5-10 nm MNPs loaded on CN uniformly (CuNPs/CN, FeNPs/CN, NiNPs/CN and CoNPs/CN). These porous MNPs/CN nanozymes were used for electrochemical detection of DA, AA and FZ, showing good performance. The electrochemical sensor based on CuNPs/CN nanozymes was used to simultaneously measure DA and UA. The linear range of DA detection was 0.015 mu-140 mu M, the linear range of UA detection was 0.03 mu M-175 mu M, and the sensitivity of DA and UA were 1.03 mu A mu M-1 cm(-2) and 0.52 mu A mu M-1 cm(-2). The sensitivity of sensors based on FeNPs/CN, CoNPs/CN and NiNPs/CN nanozymes to detect DA were 1.30 mu A cm(-2) mu M-1, 1.07 mu A cm(-2) mu M-1 and 0.88 mu A cm(-2) mu M-1, the linear ranges were 35 nM-200 mu M, 42 nM-250 mu M and 52 nM-250 mu M. The sensitivity of detecting UA were 0.310 mu A cm(-2) mu M-1, 0.587 mu A cm(-2) mu M-1 and 0.360 mu A cm(-2) mu M-1, the linear ranges were 145 nM-900 mu M, 77 nM-700 mu M and 125 nM-800 mu M. Finally, CuNPs/CN was also used to construct a FZ sensor with a linear range of 61.5 nM-200 mu M and a detection limit of 20.1 nM. The sensors also have good reproducibility and repeatability.