Facile electrochemiluminescence sensing platform based on water-soluble tungsten oxide quantum dots for ultrasensitive detection of dopamine released by cells.

This report outlines an ultrasensitive electrochemiluminescence (ECL) sensing platform based on water-soluble tungsten oxide quantum dots (WOx QDs) for the detection of dopamine (DA) released from P12 cells. The WOx QDs with good stability and water solubility were prepared by a facile and green hydrothermal method, and used to modify a glassy carbon electrode (WOx QDs/GCE). The proposed ECL sensor exhibited a stable and strong cathodic ECL signal when potassium peroxodisulfate (K2S2O8) as the coreactant in aqueous solution. The possible ECL mechanism was studied and deduced, and the ECL response signal of the proposed sensor decreased rapidly in the presence of dopamine (DA). Under optimal conditions, the ECL signals of WOx QDs linearly decreased with the increase of DA concentration in the range of 10-15 M to 10-9 M and 10-9 M to 10-5 M, respectively. The detection limit was as low as 10-15 M (S/N = 3). Based on these results, this method has been successfully applied to the determination of DA released by PC12 cells. The detection linear range for the detection of DA released by PC12 cells was from 0.1 to 0.9 μM with a detection limit of 0.045 μM. Therefore, the proposed ECL sensor displayed high sensitivity, good specificity and long-term stability, which may shed light on a new way to construct other high-performance ECL detection systems based on WOx or WOx QDs-based nanocomposites.