A novel aptameric biosensor based on the self-assembled DNA

By Li, Aixue; Zhang, Jian; Qiu, Jichuan; Zhao, Zhenhuan; Wang, Cheng; Zhao, Chunjiang; Liu, Hong
Published in Talanta NULL 2017

Abstract

Abstract It has been reported that tungsten disulfide (WS2) can bind single-stranded {DNA} (ssDNA) with high affinity while it has less affinity toward double stranded {DNA} (dsDNA). In this work, for the first time, the high affinity between {WS2} and ssDNA was used to construct stable sensing interface for {ATP} detection. A {DNA} sequence with -SH at one end was first immobilized on Au electrode. {WS2} nanosheets were immobilized on the SH-DNA/Au electrode surface due to the strong affinity between {WS2} and ssDNA. Then the {WS2} nanosheets were used to immobilize {ATP} binding aptamer (ABA) through the high affinity between {WS2} and ssDNA, too. When {ATP} reacts with the {ABA} aptamer, duplex will be formed and dissociated from the {WS2} nanosheets. On the basis of this, an electrochemical aptasensor for {ATP} was fabricated. This {ATP} sensor showed high sensitivity, selectivity and stability due to the unique WS2-ssDNA interactions and the specific aptamer-target recognition. Furthermore, this strategy was generalized to detect Hg2+ using a mercury-specific aptamer (MSO). This strategy can be expected to offer a promising approach for designing high-performance electrochemical aptasensors for a spectrum of targets.

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