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  • 02월 23일 15시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

An enzyme labeled electrochemical biosensor based on competition between aptamer-complementary DNA couple and aptamer-target biomolecule couple

2009년 2월 6일 14시 35분 01초
38P276포 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
금 <발표Ⅲ>
저자 및
윤혜원, 곽주현
KAIST 화학과, Korea
Aptamer, in vitro selected functional oligonucleotides, has been applied various biosensors due to its inherent selectivity, affinity, and diverse advantages. Many biosensors based on aptamer used electrochemical biomarkers to detect biomolecules and few of them employed enzyme label for signal amplification. [1] Signal amplification is one of the most important strategies in lowering detection limit of biosensors. Enzyme labels have been widely used in biosensor because they can generate many electroactive signal reporting molecules. [2] Here we report a signal amplified electrochemical aptasensor using competitive between aptamer-complementary DNA couple and aptamer-target biomolecule couple. The gold electrode was modified with self-assembled monolayers of thiol modified aptamers. Continually the aptamers make DNA double helix with biotinylated complementary DNAs. In the absent of target biomolecules, strepavidin-conjugated alkaline phosphatase(ALP) can bind to the biotin. But in the presence, the target biomolecules replace the complementary DNA sequence so that the strepavidin-conjugated ALP can’t bind. It needs that the binding affinity between aptamer and target biomolecule is much higher than that of aptamer-complementary DNA couple, and we can make this circumstance by reducing the number of complementary binding base pairs of double helix. The competition results in a decrease of the enzyme product which can be detectable by electrochemical methods.