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 μ–140 μM, the linear range of UA detection was 0.03 μM–175 μM, and the sensitivity of DA and UA were 1.03 μA μM−1cm−2and 0.52 μA μM−1cm−2. The sensitivity of sensors based on FeNPs/CN, CoNPs/CN and NiNPs/CN nanozymes to detect DA were 1.30 μA cm−2μM−1, 1.07 μA cm−2μM−1and 0.88 μA cm−2μM−1, the linear ranges were 35 nM–200 μM, 42 nM–250 μM and 52 nM–250 μM. The sensitivity of detecting UA were 0.310 μA cm−2μM−1, 0.587 μA cm−2μM−1and 0.360 μA cm−2μM−1, the linear ranges were 145 nM–900 μM, 77 nM–700 μM and 125 nM–800 μM. Finally, CuNPs/CN was also used to construct a FZ sensor with a linear range of 61.5 nM–200 μΜ and a detection limit of 20.1 nM. The sensors also have good reproducibility and repeatability.Keywords:electrochemical sensor;covalent-organic framework;nanozymes;carbon nanosheets