Electrochemiluminescence of CdSe Quantum Dots Composited with Nitrogen-Doped Carbon Nanotubes

A nanocomposite of CdSe quantum dots with nitrogen-doped carbon nanotubes was prepared for enhancing the electrochemiluminescent (ECL) emission of quantum dots. With hydrogen peroxide as co-reactant, the nanocomposite modified electrode showed a cathodic ECL emission with a starting potential of -0.97 V (vs. Ag/AgCl) in phosphate buffer solution, which was five-times stronger than that from pure CdSe quantum dots and three-times stronger than that from CdSe quantum dots composited with carbon nanotubes. The latter showed a starting potential of -1.19 V. This result led to a sensitive ECL sensing of hydrogen peroxide with good stability, acceptable reproducibility and a detection limit down to 2.1 x 10(-7) mol L-1. Nitrogen-doped carbon nanotubes could be used as a good material for the construction of sensitive ECL biosensors for chemical and biochemical analysis.