title: Intercalation of quantum dots as the new signal acquisition and amplification platform for sensitive electrochemiluminescent detection of microRNA.
abstract: Herein, we report on the development of a simple and sensitive biosensor for electrochemiluminescent (ECL) detection of microRNAs (miRNA) based on the intercalation of doxorubicin-conjugated quantum dot nanoparticles (Dox-QDs) into the DNA/RNA hybrids as the new signal acquisition and amplification platform. The thiolated DNA capture probes are self-assembled onto gold electrodes via the formation of Au-S bonds. The sensing surface is then incubated in a target miRNA-containing buffer solution to form the double-stranded duplexes. In this case, massive Dox-QDs can intercalate into the base pairs of the hybrid duplexes, resulting in amplified ECL emissions due to their reactions with the coreactant [Formula: see text] and the dissolved oxygen in the detection buffer. The increase in ECL intensity proportional to the amount of target miRNA in the testing samples serves as the quantitative basis. Different from traditional QDs-based methods such as labeling and embedding, our sensor involves the employment of the intercalation of the Dox-QDs as the signal acquisition and amplification platform. The combination of the QDs intercalation amplification with the high sensitivity of the ECL technique enables us to detect miRNA down to the low femtomolar level. Moreover, our method is also coupled with acceptable selectivity in discriminating the target miRNA and against its family members as well as other interference sequence, and can monitor miRNAs from human prostate carcinoma (22Rv1) cell lysates.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China; College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yunatswu@swu.edu.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yuanruo@swu.edu.cn.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
mesh_terms: D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry*; D004317:Doxorubicin / Q000031:analogs & derivatives*; D055664:Electrochemical Techniques / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D007364:Intercalating Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D035683:MicroRNAs / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*
chemical_list: D007364:Intercalating Agents; D035683:MicroRNAs; D004317:Doxorubicin; D004247:DNA
keywords: Doxorubicin; Electrochemiluminescence; MicroRNA; Quantum dot