An electrochemical ratiometric sensor based on 2D MOF nanosheet/Au/polyxanthurenic acid composite for detection of dopamine

In this study, a novel Cu-based metal−organic frameworks (Cu-MOFs) composite material was prepared, and used to develop a sensitive and efficient electrochemical ratiometric sensor for dopamine detection. Gold nanoparticles (NPs) and the conductive poly(xanthurenic acid) p(XA) were assembled on the Cu-tetrakis (4-carboxyphenyl) porphyrin (TCPP) surface by electrodeposition and cyclic voltammetry (CV) method, which greatly improved the electrocatalytic performance of the Cu-MOF modified electrode. Two substances (dopamine/DA, paracetamol/PA) with different electrochemical peaks were added to the electrolyte solutions, where DA was the analyte and PA was as a reference. The ratiometric value of differential pulse voltammetry (DPV) oxidation current (IDA/IPA) linearly increased with the increasing concentration of DA with low detection limit. This electrochemical ratiometric approach based on the metal−organic framework composites is expected to be a valuable strategy for detection of other analytes.