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Digital multimeter-based immunosensing strategy for sensitive monitoring of biomarker by coupling an external capacitor with an enzymatic catalysis.
- Source :
-
Biosensors & Bioelectronics . May2014, Vol. 55, p255-258. 4p. - Publication Year :
- 2014
-
Abstract
- Abstract: A new digital multimeter (DMM)-based immunosensing system was designed for quantitative monitoring of biomarker (prostate-specific antigen, PSA used in this case) by coupling with an external capacitor and an enzymatic catalytic reaction. The system consisted of a salt bridge-linked reaction cell and a capacitor/DMM-joined electronic circuit. A sandwich-type immunoreaction with target PSA between the immobilized primary antibody and glucose oxidase (GOx)-labeled detection antibody was initially carried out in one of the two half-cells. Accompanying the sandwiched immunocomplex, the conjugated GOx could catalyze the oxidation of glucose, simultaneously resulting in the conversion of [Fe(CN)6]3− to [Fe(CN)6]4−. The difference in the concentrations of [Fe(CN)6]3−/[Fe(CN)6]4− in two half-cells automatically produced a voltage that was utilized to charge an external capacitor. With the closing circuit switch, the capacitor discharged through the DMM, which could provide a high instantaneous current. Under the optimal conditions, the resulting currents was indirectly proportional to the concentration of target PSA in the dynamic range of 0.05–7ngmL−1 with a detection limit (LOD) of 6pgmL−1. The reproducibility, precision, and selectivity were acceptable. In addition, the methodology was validated by analyzing 12 clinical serum specimens, receiving a good accordance with the referenced values for the detection of PSA. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09565663
- Volume :
- 55
- Database :
- Academic Search Index
- Journal :
- Biosensors & Bioelectronics
- Publication Type :
- Academic Journal
- Accession number :
- 94307643
- Full Text :
- https://doi.org/10.1016/j.bios.2013.12.022