A sensitive biosensor for dopamine determination based on the unique catalytic chemiluminescence of metal-organic framework HKUST-1

In this work, it was reported that Cu-BTC (HKUST-1) can excellently catalyze the chemiluminescence (CL) reaction of luminol-H2O2 system in an alkaline medium for the first time. Compared with the luminol-H2O2 system, the CL intensity of luminol-H2O2-HKUST-1 system was enhanced significantly up to about 90-fold, which formed the sensitized CL system. The presence of dopamine (DA) inhibited the luminol-H2O2 HKUST-1 system, thus causing the changes in CL intensity (Delta I). Based on this phenomenon, the excellent sensing platform for detection of DA was established. Under the optimized conditions, the Delta I was proportional to the concentration of DA in the range of 0.0100.70 mu M with the detection limit of 2.3 nM (3S/N). The proposed method was applied to the determination of DA in human plasma and urine samples with satisfactory results. Furthermore, the corresponding mechanism of such enhancement was investigated. The results indicated that the enhancement in CL intensity of the luminol-H2O2-HKUST-1 system originated from the catalysis of HKUST-1, which facilitated the radical generation and electron-transfer processes on its surface.