Rational Confinement of Yttrium Vanadate within Three-Dimensional Graphene Aerogel: Electrochemical Analysis of Monoamine Neurotransmitter (Dopamine)

An easy prepared fluorometric and colorimetric dual channel probe is developed for dopamine (DA) detection with high sensitivity and selectivity by use of BSA-stabilized Au nanoclusters (BSA-AuNCs). The BSA-AuNCs exhibit strong fluorescence emission, while upon addition of DA, the AuNCs show a dramatic decrease of the fluorescence intensity as a result of the photo-induced electron transfer process from the electrostatically attached DA to the BSA-AuNCs. The detection limit of DA can be as low as 10 nM. In addition, the assay for DA can also be easy to implement for visual detection due to the observed inhibition of the peroxidase-like activity of AuNCs in the presence of DA, with a detection limit of 10 nM. Both fluorometric and colorimetric methods exhibit excellent selectivity toward DA over interfering substances. Furthermore, we demonstrate the application of the present approach in hydrochloride injection sample, human serum sample and PC12 cells, which suggests its great potential for diagnostic purposes. Copyright © 2012 Elsevier B.V. All rights reserved.

Electrogenerated chemiluminescence (ECL) emission was observed from the water-soluble, bovine serum albumin (BSA)-stabilized Au nanoclusters for the first time. The possible ECL mechanism was discussed according to the presented results and ascribed to the effective electron transfer from the conduction-band of excited indium tin oxide (ITO) to Au nanoclusters (NCs). A simple label-free method for the detection of dopamine has been developed based on the Au NCs ECL in aqueous media. The Au NCs could be an effective candidate for new types of ECL biosensors in the future due to their fascinating features, such as good water solubility, low toxicity, ease of labeling, and excellent stability.