Article ID Journal Published Year Pages File Type
869307 Biosensors and Bioelectronics 2008 7 Pages PDF
Abstract

We described a novel electrochemical DNA biosensor based on molecular beacon (MB) probe and enzymatic amplification protocol. The MB modified with a thiol at its 5′ end and a biotin at its 3′ end was immobilized on the gold electrode through mixed self-assembly process. Hybridization events between MB and target DNA cause the conformational change of the MB, triggering the attached biotin group on the electrode surface. Following the specific interaction between the conformation-triggered biotin and streptavidin-horseradish peroxidase (HRP), subsequent quantification of DNA was realized by electrochemical detection of enzymatic product in the presence of substrate. The detection limit is obtained as low as 0.1 nM. The presented DNA biosensor has good selectivity, being able to differentiate between a complementary target DNA sequence and one containing G–G single-base mismatches.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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