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A sensitive and selective electrochemiluminescent sensor for dopamine based on the inhibition of dual-stabilizer-capped CdS quantum dot electrochemiluminescence

Yang, Minli, Yang, Xuemei, Wang, Mingli, Jiang, Rui
Analytical methods 2017 v.9 no.15 pp. 2334-2341
analytical methods, biochemical compounds, carbon electrodes, carbon nanotubes, chemical bonding, detection limit, dopamine, electrochemiluminescence, glass, p-aminobenzoic acid, quantum dots, silver, silver chloride
An electrochemiluminescent (ECL) sensor with dual-stabilizer-capped CdS quantum dots (QDs) as an ECL emitter was constructed and used for the determination of dopamine (DA). The dual-stabilizer-capped CdS QDs were covalently immobilized onto a p-aminobenzoic acid (ABA) modified glass carbon electrode with 1,3-propylene amide (PDA) as a link molecule. The introduction of multiwalled carbon nanotubes (MWCNTs) into the electrode increased the ECL signal to 1.5 times. The proposed sensor produced a strong ECL signal under −1.4 V (vs. Ag/AgCl) and the signal could be quenched by DA which can be used for the detection of DA in the range of 5.0 × 10⁻⁹ to 5.0 × 10⁻⁶ mol L⁻¹. The detection limit was 1.6 × 10⁻⁹ mol L⁻¹. This strategy provides a potential approach to constructing ECL sensors for other biomolecules.