Aptamer-Based electrochemiluminescent detection of MCF-7 cancer cells based on carbon quantum dots coated mesoporous silica nanoparticles

In this work, we developed a novel electrochemiluminescence (ECL) platform for ultrasensitive and selective detection of MCF-7 cancer cells. To construct the platform, three-dimensional macroporous AuNPs@graphene complex was prepared through freeze drying process to modify glassy carbon electrode, which provided an effective matrix for concanavalin A to capture cancer cells due to its high surface area-to-weight ratio and excellent mechanical properties. The carbon quantum dots ( CQDs) coated mesoporous silica nanoparticles were used as excellent ECL tracers due to their low cytotoxicity and good biocompatibility. Then, the prepared tracers were conjugated with mucinl aptamer to specifically bind mucinl on cancer cells with high stability and bioactivity. Structure characterization was obtained by means of transmission electron microscopy and scanning electron microscopy images. The proposed method showed a good analytical performance for the detection of MCF-7 cancer cells ranging from 500 to 2 x 10(7) cells mL(-1) with a detection limit of 230 cells mL(-1). The as-proposed device has the advantages of high sensitivity, nice specificity, and good stability and could offer great promise for sensitive detection of MCF-7 cancer cells in response to therapy. (C) 2014 Elsevier Ltd. All rights reserved.