Highly sensitive electrochemiluminescent DNA biosensor based on hydrazide-modified graphene quantum dots and hemin/G-quadruplex DNAzyme

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• 作者：Xiaoying Wang ; Li Liu ; Zhaoyin Wang ; Zhihui Dai ; ^{daizhihuii@njnu.edu.cn}
• 关键词：Electrochemiluminescent biosensor ; Hydrazide modified graphene quantum dots ; Hemin/G-quadruplex DNAzyme ; p53 gene
• 刊名：Journal of Electroanalytical Chemistry
• 出版年：2016
• 出版时间：15 November 2016
• 年：2016
• 卷：781
• 期：Complete
• 页码：351-355
• 全文大小：709 K
• 卷排序：781

文摘

Graphene quantum dots (GQDs), an alternative of conventional luminescent reagents, has been widely used in electrochemiluminescent (ECL) analysis because of its low cost, non-toxicity and ease of preparation. To further improve the ECL signal of GQDs, we herein succeeded in synthesizing hydrazide modified graphene quantum dots (HM-SGQDs). In comparison with GQDs, HM-SGQDs possessed abundant luminol like units, thus greatly enhancing the ECL intensity. On the other hand, luminol involved ECL system typically needed the participation of H2O2 as a coreactant, while hemin/G-quadruplex DNAzyme (hGQ) DNAzyme could efficiently catalyze the decomposition of H2O2. Accordingly, taking p53 gene as a model, a novel ECL DNA biosensor was developed based on HM-SGQDs and hGQ DNAzyme. The experimental results indicated target DNA can be quantified in a linear range from 100 fM to 100 nM with a detection limit of 66 fM (S/N = 3). Meanwhile, the discrimination of single-base mismatch was also achieved with the proposed analytical approach, suggesting broad potential applications of nucleic acid-related clinical diagnosis.