Dual Enhanced Electrochemiluminescence of Aminated Au@SiO2/CdS Quantum Dot Superstructures: Electromagnetic Field Enhancement and Chemical Enhancement

This paper reports dual enhanced electrochemiluminescence (ECL) of CdS quantum dot (QD)-decorated aminated Au@SiO2 core/shell (Au@SiO2-NH2/CdS) superstructures. A maximum ECL emission of the Au@SiO2-NH2/CdS superstructures (Au core, ca. 55 nm) with a silica shell of 38 nm was 35-fold stronger than that of the counterparts (containing neither Au cores nor amino groups) with H2O2 as a coreactant. The fold of ECL enhancement is the largest, and the optical path of maximum ECL enhancement is the longest reported so far. The larger the Au cores in the superstructures, the stronger the ECL emission of CdS QDs was. Two types of ECL enhancement mechanisms were clearly proposed for the dual enhanced ECL of the Au@SiO2-NH2/CdS superstructures. One was the electromagnetic field enhancement induced by localized surface plasmon resonance of Au cores, and the other was the chemical enhancement from amino groups modified on the silica surface involved in the ECL process in the assistance of H2O2. It is the first time to...