Ultrasensitive direct detection of dsDNA using a glassy carbon electrode modified with thionin-functionalized multiple graphene aerogel and gold nanostars

详细信息    查看全文

• 作者：Li Ruiyi ; Wang Jiajia ; Liu Ling ; Li Zaijun
• 刊名：Microchimica Acta
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：183
• 期：5
• 页码：1641-1649
• 全文大小：518 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Analytical Chemistry
  Inorganic Chemistry
  Physical Chemistry
  Characterization and Evaluation Materials
  Monitoring, Environmental Analysis and Environmental Ecotoxicology
  
• 出版者：Springer Wien
• ISSN：1436-5073
• 卷排序：183

文摘

The paper reports on the synthesis of a composite consisting of thionin-functionalized multiple graphene aerogel and gold nanostars (termed TF-MGA/GNSs). The composite displays an enhanced electrochemical performance compared to the classical graphene aerogel. The performance can be further improved by increasing number of the graphene oxide gelation cycles. The composite was deposited on a glassy carbon electrode to obtain a biosensor for the direct detection of dsDNA. The interaction of thionin with dsDNA causes a specific electrochemical response, best at a working voltage of −228 mV (vs. Ag/AgCl). The enhanced electrocatalytic activity of the composite strongly improves sensitivity. The differential pulse voltammetric signal linearly decreases with increasing dsDNA concentration in the range from 100 fg · mL−1 to 10 ng · mL−1, and the detection limit is 39 fg · mL−1 (at an S/N ratio of 3). The method is sensitive, selective and rapid. It was successfully applied to the detection of circulating free DNA in human serum. The study also provides an attractive approach towards graphene aerogel-based materials to meet the needs of nanoelectronics for molecule diagnosis, bioanalysis and catalysis.