Preparation of iron porphyrin/calix[8]arene/graphene ternary composites based on molecular recognition function and their dopamine electrochemical sensing properties

Abstract

<p indent="0mm">In this paper, tetrabiphenylporphyrin iron (FeTBPP) with electrocatalytic activity and <italic>p</italic>-<italic>tert</italic>-butyl calix[8]arene (C[8]A) with specific molecular recognition functions were self-assembled onto highly conductive graphene oxide (GO) by interfacial self-assembled method to obtain FeTBPP/C[8]A/GO composite film. The structural characterization for the composite film showed that the FeTBPP grew on the conjugated plane of GO by π-π interaction, while C[8]A molecules combined with GO by the hydrogen bond. These ensure good dispersion of the two kinds of molecules on the GO template. Compared with the single component films of the two kinds of molecules, the composite films have significantly improved surface morphology and higher conductivity. The electrochemical test showed that the response current is linear with dopamine (DA) concentration, with a wide detection range of 0.1–1000 μM, high sensitivity of 17.6 μA/mmol and LOD of 25.6 nM. More importantly, depending on the anchoring and dispersing effects of GO on FeTBPP and C[8]A, the detection of DA by composite electrode has high stability, reproducibility and selectivity. The sensor was applied to human urine and serum samples, and the highly sensitive detection of DA was successfully realized.