An Electrochemical Sensor for DNA Detection Based Metal Nanoparticle Modified with Cyclodextrins

Abstract:

We herein constructed a sensor that converts target DNA hybridization-induced conformational transformation of the probe DNA to electrochemical response based on host-guest recognition and nanoparticle label. In the sensor, the hairpin DNA terminal-labeled with 4-((4-(dimethylamino) phenyl) azo) benzoic acid (dabcyl) and thiol group was immobilized on Au electrode surface as the probe DNA by Au-S bond, and the PdS nanoparticles surface-modified with β-cyclodextrins (PdS-CDs) were employed as electrochemical signal provider and host-guest recognition element. Initially, the probe DNA immobilized on electrode kept the stem-loop configuration, which shielded dabcyl from docking with the PdS-CDs in solution due to the steric effect. After target hybridization, the probe DNA underwent a significant conformational change, which forced dabcyl away from the electrode. As a result, formerly shielded dabcyl became accessible to host-guest recognition between β-cyclodextrin and dabcyl, thus the target hybridization event could be sensitively transduced to electrochemical signal provided by PdS-CDs. This host guest recognition-based electrochemical sensor has been able to detect as low as picomolar DNA target with excellent differentiation ability for even single mismatch

• Periodical: Applied Mechanics and Materials (Volume 391)
• Pages: 332-335
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.391.332
• Online since: September 2013
• Authors: Hao Fan, Lin Cheng, Han Feng Cui
• Keywords: Cyclodextrins, DNA, Electrochemical Sensor, Nanoparticle

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