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Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor
Published on: February 16, 2018
Ultrasensitive electrochemical biosensor based on the oligonucleotide self-assembled monolayer-mediated immunosensing
Dengyou Liu1, Qimei Luo1, Fawen Deng2
1Science College of Hunan Agricultural University, Changsha 410128, PR China.
Insights
A new electrochemical immunosensor offers highly sensitive protein detection. This biosensor platform utilizes oligonucleotide self-assembled monolayers for enhanced accuracy in biomarker detection and disease diagnostics.
Area of Science:
- Biosensors
- Electrochemistry
- Biomarker Detection
Background:
- Accurate protein quantitation is crucial for disease diagnostics.
- Existing methods often lack sensitivity or specificity.
- Developing ultrasensitive and selective biosensors is a key research area.
Purpose of the Study:
- To develop an electrochemical immunosensing platform for highly sensitive and selective protein detection.
- To utilize an oligonucleotide self-assembled monolayer (OSAM) for improved biosensing performance.
- To demonstrate the platform's capability using human immunoglobulin G (HIgG) as a model.
Main Methods:
- Fabrication of an electrochemical biosensor using a gold electrode modified with thiolated single-stranded DNA (OSAM).
- Integration of a "signal-on" mechanism and enzymatic signal amplification.
- Electrochemical detection of HIgG using cyclic voltammetry or impedance spectroscopy.
Main Results:
- The OSAM interface facilitated electron transfer and prevented non-specific protein adsorption.
- The immunosensor achieved ultrasensitive detection of HIgG down to 0.5 ng/mL.
- High specificity was demonstrated, minimizing cross-reactivity.
Conclusions:
- The developed OSAM-mediated electrochemical immunosensor provides a robust platform for protein detection.
- The biosensor exhibits high sensitivity and selectivity, suitable for biomarker detection.
- Oligonucleotide probes show significant potential for biological research and biomedical diagnostics.
Abstract:
Highly sensitive and selective quantitation of a variety of proteins over a wide concentration range is highly desirable for increased accuracy of biomarker detection or for multidisease diagnostics. In the present contribution, using human immunoglobulin G (HIgG) as the model target protein, an electrochemical ultrasensitive immunosensing platform was developed based on the oligonucleotide self-assembled monolayer-mediated (OSAM) sensing interface. For this immunosensor, the "signal-on" signaling mechanism and enzymatic signal amplification effect were integrated into one sensing architecture. Moreover, the thiolated flexible single-stranded DNAs immobilized onto gold electrode surface not only performs the wobbling motion to facilitate the electron transfer between the electrode surface and biosensing layer but also fundamentally prohibiting the direct interaction of proteins with gold substrate. Thus, the electrochemical signal could be efficiently enhanced and the unspecific adsorption or cross-reaction might be eliminated. As a result, utilizing the newly-proposed immunosensor, the HIgG can be detected down to 0.5 ng/mL, and the high detection specificity is offered. The successful design of OSAM and the highly desirable detection capability of new immunosensor are expected to provide a perspective for fabricating new robust immunosensing platform and for promising potential of oligonucleotide probe in biological research and biomedical diagnosis.
