Sensitive DNA biosensor improved by 1,10-phenanthroline cobalt complex as indicator based on the electrode modified by gold nanoparticles and graphene

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• 作者：Shuyan Niu ; ^{wenzhangggg@126.com}Author Vitae ; Juan SunAuthor Vitae ; Chuncai NanAuthor Vitae ; Jiehua LinAuthor Vitae
• 关键词：1 ; 10-Phenanthroline cobalt ; Graphene ; Gold nanoparticles ; Electrochemical DNA biosensor
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：176
• 期：Complete
• 页码：58-63
• 全文大小：690 K

文摘

A novel and sensitive electrochemical DNA biosensor was constructed based on the gold electrode modified by graphene and gold nanoparticles (AuNPs), whose sensitivity was improved by using 1,10-phenanthroline cobalt ([Co(phen)₂(Cl)(H₂O)]⁺) as an electroactive indicator. The gold electrode was firstly modified with sulfur graphene (GR-SH), and then covalently grafted with AuNPs via sulfur-gold affinity. Finally the thiol capped probe DNA was immobilized onto the AuNPs/GR modified electrode. The target DNA could hybridize with the probe DNA to form a double-stranded DNA (ds-DNA), into which [Co(phen)₂(Cl)(H₂O)]⁺ can intercalate, which can be confirmed by cyclic voltammetry (CV). The target DNA, from Escherichia coli (E. coil), could be detected in a linear range from 2.50 ¡Á 10^?11 to 1.25 ¡Á 10^?9 M (R = 0.9981) with a detection limit of 8.33 ¡Á 10^?12 M (3¦Ò, n = 11). It was demonstrated that the reported electrochemical DNA biosensor offered a promising approach for the sensitive and selective detection of DNA by using [Co(phen)₂(Cl)(H₂O)]⁺ as an electroactive indicator.