Electrochemical sensor based on covalent organic frameworks-MWCNT-NH2/AuNPs for simultaneous detection of dopamine and uric acid

An electrochemical sensing platform for simultaneous determination of dopamine (DA) and uric acid (UA) is constructed based on covalent organic framework materials (IL COF-1), aminofunctionalized carbon nanotubes (MWCNT-NH2), and gold nanoparticles (AuNPs). The prepared sensor shows a good performance in detection of DA and UA due to porosity, large specific surface area, high conductivity and more active sites of the composite modified material. Under optimized experimental conditions, the constructed electrochemical sensor has sensitive response and good linearity to both DA and UA. Their wide linear ranges are 0.7?108 ?M and 0.97?200 ?M, and the detection limits are 0.21 ?M and 0.29 ?M (S/N = 3), respectively. The developed method has been successfully employed to determine the contents of DA and UA in dopamine injection and human urine samples. It has a satisfactory recovery rate, and the relative standard deviations (RSD) of three parallel determinations are all below 5.0%. In comparison, the constructed sensor platform has superior performance including low cost, simple structure, wide linear range and high sensitivity than some traditional methods, which is expected to be widely used in real sample analysis.