Preparation of porphyrin derivatives and C60 supramolecular assemblies as a sensor for detection of dopamine

The non-covalent self-assembly of porphyrin-diazocine-porphyrin (PDP) with fullerene (C-60) in toluene and dichloromethane solution was investigated using H-1 NMR spectroscopy, UV-vis spectroscopy, fluorescence spectroscopy and electrochemical experiments. H-1 NMR suggested that the atoms on the porphyrin ring are in strong interaction with the C-60 surface. Optical (UV-vis and fluorescence) and electrochemical studies confirmed the supramolecular interactions occur between PDP and C-60. The PDP-C-60/GCE composite-modified electrode was prepared and characterized using SEM. The electrochemical activity of dopamine (DA) was evaluated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The oxidation peak current (I-pa) increased linearly with increasing concentration of DA in the range of 0-200 mu M, and the detection limit was 0.015 mu M with a high sensitivity. The influence of some common ions and other organics on the detection of DA was studied with satisfactory selectivity. In addition, the sensor showed excellent repeatability and stability for the detection of DA.