Label-Free Sensing of Adenosine Based on Force Variations Induced by Molecular Recognition

Biosensors

Jingfeng Li¹  Qing Li¹  Lucio Colombi Ciacchi¹  Gang Wei¹ 

[1] Hybrid Materials Interfaces Group, Faculty of Production Engineering, University of Bremen, Am Fallturm 1, 28359 Bremen, Germany; E-Mails:

关键词: label-free sensing;    adenosine;    AFM;    single-molecule force spectroscopy;    aptamer;    molecular recognition;   

DOI  :  10.3390/bios5010085

来源: mdpi

【 摘 要 】

We demonstrate a simple force-based label-free strategy for the highly sensitive sensing of adenosine. An adenosine ssDNA aptamer was bound onto an atomic force microscopy (AFM) probe by covalent modification, and the molecular-interface adsorption force between the aptamer and a flat graphite surface was measured by single-molecule force spectroscopy (SMFS). In the presence of adenosine, the molecular recognition between adenosine and the aptamer resulted in the formation of a folded, hairpin-like DNA structure and hence caused a variation of the adsorption force at the graphite/water interface. The sensitive force response to molecular recognition provided an adenosine detection limit in the range of 0.1 to 1 nM. The addition of guanosine, cytidine, and uridine had no significant interference with the sensing of adenosine, indicating a strong selectivity of this sensor architecture. In addition, operational parameters that may affect the sensor, such as loading rate and solution ionic strength, were investigated.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.