Magnetic force assisted electrochemical sensor for the detection of thrombin with aptamer-antibody sandwich formation
Autor: | Saeromi Chung, Jong-Min Moon, Yoon-Bo Shim, Jaekyu Choi, Hyundoo Hwang |
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Rok vydání: | 2018 |
Předmět: |
Streptavidin
Materials science Aptamer Biomedical Engineering Biophysics Nanoparticle Biosensing Techniques 02 engineering and technology 01 natural sciences Magnetics chemistry.chemical_compound Thrombin Electrochemistry medicine Electrodes Voltammetry Detection limit 010401 analytical chemistry Reproducibility of Results General Medicine Aptamers Nucleotide 021001 nanoscience & nanotechnology 0104 chemical sciences Electrochemical gas sensor Dielectric spectroscopy chemistry 0210 nano-technology Blood Chemical Analysis Biotechnology Nuclear chemistry medicine.drug |
Zdroj: | Biosensors and Bioelectronics. 117:480-486 |
ISSN: | 0956-5663 |
Popis: | A magnetic force assisted electrochemical aptamer-antibody sandwich assay (MESA) was developed for the detection of thrombin as a model protein in serum samples. The MESA using the formation of sandwich complexes on the electrochemical sensor probe for reaction and the removal of unbound bioconjugates from the sensor surface without washing are controlled by a magnetic field. Thrombin was determined by the cathodic currents of a toluidine blue O (TBO) attached with thrombin antibody modified magnetic nanoparticle (MNP) at the sensor surface. To detect thrombin in a serum sample, we applied a thrombin-specific aptamer as the capture molecule bound to the functionalized conducting polymer layer (poly-(2,2´:5´,5″-terthiophene-3´-p-benzoic acid) (pTBA)), and streptavidin and starch coated-MNP was conjugated with biotinylated thrombin antibodies (Ab) and TBO as the bioconjugate (MNP@Ab-TBO). The characterization of MNP@Ab-TBO and sensor probe was performed using voltammetry, impedance spectroscopy, XPS, and UV–VIS spectroscopy. The experimental conditions were optimized in terms of pH, binding time, removal time of unbound bioconjugates, and applied potential. The dynamic ranges of thrombin were from 1.0 to 500 nM with detection limit of 0.49 ( ± 0.06) nM. The recovery test demonstrates the reliability of the proposed sensing system for a handheld device. |
Databáze: | OpenAIRE |
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