A novel strategy for constructing electrochemiluminescence sensor based on CdS-polyamidoamine incorporating electrodeposited gold nanoparticle film and its application

In this study, a novel strategy for the construction of CdS quantum dots (QDs)-based electrochemiluminescence (ECL) sensor was developed. The stable nanocomposite film was obtained by using self-assembly CdS QDs capped with polyamidoamine (short for CdS-PAMAM) incorporating electrodeposited gold nanoparticles onto the surface of Au electrode. The water soluble CdS-PAMAM QDs were successfully synthesized by using PAMAM as a template and stabilizer. Based on the numerous reactive groups on the dendrimers, the high uniform and well-dispersed CdS-PAMAM QDs were assembled onto the surface of electrodeposited gold nanoparticles film. The feasibility of this manner was confirmed by photoluminescence, absorption spectra, scanning electron microscopy and electrochemical measurements. In addition, the ECL performance of the constructed CdS-PAMAM/GNPs film was investigated. With the synergistic effect of the CdS-PAMAM QDs and electrodeposited gold nanoparticles, the ECL response was dramatically enhanced. The fabricated nanocomposite film demonstrated rather high stability and sensitivity to dopamine detection. Under optimal experimental conditions, the fabricated sensor responded linearly to dopamine concentration in the range of 0.05–10 μmol L−1 with a detection limit of 0.012 μmol L−1. Moreover, the sensor exhibited good specificity, stability and reproducibility. The present work shows promising potential for developing new efficient ECL sensor.