▎ 摘　　要

In this work, boron doped graphene quantum dots (BGQDs) with the atomic percentage of boron (B) of 0.67-2.26% were synthesized by electrolytic exfoliation of B doped graphene rods. X-ray photoelectron spectroscopy of BGQDs confirmed that the B atoms have been successfully incorporated into the GQDs. Characterizations by transmission electron microscopy, photoluminescence (PL) spectra and UV -visible spectra demonstrated that BGQDs had a consistent lattice spacing with the plane of graphene and possessed good luminous performance. The PL stability, the electrochemical impedance and Zeta potential test indicated that the 60 days -PL stability of BGQDs was improved by 51% and the resistance of BGQDs was decreased by 11% compared with that of the pure GQDs when 1.29% (atomic percentage) of B was doped. Electrochemiluminescence (ECL) sensing results showed that the ECL sensor with BGQDs as luminescent material exhibited an excellent analytical property for the detection of miRNA-20a in a linear range of 0.1-1 x104 pM with a quantification limit of 0.1 pM. Specificity tests showed that this ECL sensor could distinguish the target miRNAs-20a with several similar bases strand. The obtained results in this study prove that the proposed ECL sensor provides a high sensitively, specifically and simply platform for detection of miRNAs-20a. (C) 2015 Elsevier Ltd. All rights reserved.