Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 14, Issue 1, Pages 150-158Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.1c17243
Keywords
nanoporous alumina; anodization; computational electrochemical impedance spectroscopy (EIS); label-free; aptasensor; sensing mechanism
Funding
- NIDDK Institute of the National Institutes of Health [5R44DK098031]
- U.S. Department of Energy (DOE), Office of Biological and Environmental Research, Biological Systems Science Division under FWP [AL-18-380-055]
- U.S. Department of Energy by Iowa State University [DE-AC02-07CH11358]
- ISU Plant Science Institute
Ask authors/readers for more resources
The study presents an experimental and computational approach for developing a highly sensitive and responsive label-free biosensor based on aptamer-functionalized transparent electrode. The sensor shows sensitive and specific thrombin protein detection with a high signal-to-noise ratio. Computational and experimental results indicate that the sensing response is due to modified ionic transport under the combined influence of steric hindrance and surface charge modification.
We report an experimental and computational approach for the fabrication and characterization of a highly sensitive and responsive label-free biosensor that does not require the presence of redox couples in electrolytes for sensitive electrochemical detection. The sensor is based on an aptamer-functionalized transparent electrode composed of nanoporous anodized alumina (NAA) grown on indium tin oxide (ITO)-covered glass. Electrochemical impedance changes in a thrombin binding aptamer (TBA)-functionalized NAA/ITO/glass electrode due to specific binding of alpha-thrombin are monitored for protein detection. The aptamer-functionalized electrode enables sensitive and specific thrombin protein detection with a detection limit of similar to 10 pM and a high signal-to-noise ratio. The transient impedance of the alumina film-covered surface is computed using a computational electrochemical impedance spectroscopy (EIS) approach and compared to experimental observations to identify the dominant mechanisms underlying the sensor response. The computational and experimental results indicate that the sensing response is due to the modified ionic transport under the combined influence of steric hindrance and surface charge modification due to ligand/receptor binding between alpha-thrombin and the aptamer-covered alumina film. These results suggest that alumina film-covered electrodes utilize both steric and charge modulation for sensing, leading to tremendous improvement in the sensitivity and signal-to-noise ratio. The film configuration is amenable for miniaturization and can be readily incorporated into existing portable sensing systems.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available