Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (3): 483-488.doi: 10.3866/PKU.WHXB201501151

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Effects of Gold Nanoparticles on Quantum Dot Electrochemiluminescence Obtained Using a DNA Electrochemiluminescence Sensor

LU Li-Ping, LI Jiao, WU Jing, KANG Tian-Fang, CHENG Shui-Yuan   

  1. Key Laboratory of Beijing on Regional Air Pollution Control, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, P. R. China
  • Received:2014-12-30 Revised:2015-01-13 Published:2015-03-06
  • Contact: LU Li-Ping E-mail:lipinglu@bjut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21005005, 21375005, 21475006) and Beijing Nova Program, China (2010B009).

Abstract:

Gold nanoparticles (AuNPs) have a high extinction coefficient and a strong surface plasmon resonance, the latter of which is influenced by the size of AuNPs and the surrounding environment. In this article, a DNA electrochemiluminescence (ECL) sensor was fabricated based on the distance-dependence of semiconductor nanocrystals' ECL signal to AuNPs. AuNPs were first deposited on the surface of glassy carbon electrode (GCE) by cyclic voltammetry (CV). The mercaptopropionic acid-capped CdS quantum dots (QDs) used in this study can covalently bind with amino-terminated double-stranded DNA (dsDNA), via the ―CO―NH bond to obtain a QDs-dsDNA compound. The QDs-dsDNA compounds were assembled on the surface of AuNPs via an Au―S bond, using the other distal of dsDNA that is labeled with thiol, to create the CdS QDs-DNA/AuNPs/GCE ECL sensor. Experimental conditions, such as the QDs-dsDNA density on the surface of electrode and the deposition method of AuNPs, were then optimized. The surface properties of different modified electrodes were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS). The effect of AuNPs on the ECL intensity of CdS QDs was investigated by controlling the DNA which lies between the AuNPs and the CdS QDs. The ECL signal was affected significantly by the length and type of DNA strands. The sensor was used to detect DNA damage from environmental pollutants and exhibited a highly sensitive response.

Key words: Quantum dot, Electrochemiluminescence, Au nanoparticle, DNA, Perfluorooctanoic acid

MSC2000: 

  • O646