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

Xueyuan Li; Yang Xu; Yuxia Chen; Chen Wang; Jingjing Jiang; Jiangtao Dong; Hua Yan; Xuezhong Du

doi:10.1021/acsami.8b14886

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

ACS Appl Mater Interfaces. 2019 Jan 30;11(4):4488-4499. doi: 10.1021/acsami.8b14886. Epub 2019 Jan 15.

Authors

Xueyuan Li¹, Yang Xu¹, Yuxia Chen¹, Chen Wang¹, Jingjing Jiang¹, Jiangtao Dong¹, Hua Yan¹, Xuezhong Du¹

Affiliation

¹ Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , People's Republic of China.

PMID: 30605310
DOI: 10.1021/acsami.8b14886

Abstract

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 put forward the new concept of chemical enhanced ECL that was directly related to the participation of other chemicals, which caused a decrease in the difference in the redox potential between emitters and coreactants for the increase of their redox currents. The constructed ECL platform was demonstrated to have promising applications in highly sensitive detection of glutathione (GSH), and the response mechanism of GSH was also explored.

Keywords: Au@SiO2 nanoparticle; CdS quantum dot; chemical enhancement; electrochemiluminescence detection; electrochemiluminescence enhancement; electromagnetic field enhancement.