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Updated: Jun 24, 2026
A Microfluidic-based Electrochemical Biochip for Label-free DNA Hybridization Analysis
Published on: September 10, 2014
CSDR Coupling with Exo III for Ultrasensitive Electrochemistry Determination of miR-145
Moli Zhang1, Yang Yang1, Lingyi Xin2
1Shenzhen Bao'an Authentic TCM Therapy Hospital, Shenzhen 518102, China.
Abstract:
Recently, miRNAs have become a promising biomarker for disease diagnostics. miRNA-145 is closely related to strokes. The accuracy determination of miRNA-145 (miR-145) in stroke patients still remains challenging due to its heterogeneity and low abundance, as well as the complexity of the blood matrix. In this work, we developed a novel electrochemical miRNA-145 biosensor via subtly coupling the cascade strand displacement reaction (CSDR), exonuclease III (Exo III), and magnetic nanoparticles (MNPs). The developed electrochemical biosensor can quantitatively detect miRNA-145 ranging from 1 × 102 to 1 × 106 aM with a detection limit as low down as 100 aM. This biosensor also exhibits excellent specificity to distinguish similar miRNA sequences even with single-base differences. It has been successfully applied to distinguish healthy people from stroke patients. The results of this biosensor are consistent with the results of the reverse transcription quantitative polymerase chain reaction (RT-qPCR). The proposed electrochemical biosensor has great potential applications for biomedical research on and clinical diagnosis of strokes.
Insights
A new electrochemical biosensor accurately detects microRNA-145 (miR-145), a stroke biomarker, in blood. This innovation aids in distinguishing stroke patients from healthy individuals, improving diagnostic capabilities.
Area of Science:
- Biomedical Engineering
- Molecular Diagnostics
- Biosensor Technology
Background:
- MicroRNAs (miRNAs) show promise as disease diagnostic biomarkers.
- MicroRNA-145 (miR-145) is implicated in stroke, but its detection is challenging due to low abundance and blood matrix complexity.
- Accurate detection of miR-145 is crucial for stroke diagnostics.
Purpose of the Study:
- To develop a novel electrochemical biosensor for sensitive and specific detection of miR-145.
- To address the challenges of detecting low-abundance miRNAs in complex biological samples.
- To evaluate the biosensor's potential for clinical stroke diagnosis.
Main Methods:
- Development of an electrochemical biosensor utilizing cascade strand displacement reaction (CSDR), exonuclease III (Exo III), and magnetic nanoparticles (MNPs).
- Quantitative detection of miR-145 across a wide concentration range (1 × 10^2 to 1 × 10^6 aM).
- Assessment of specificity against similar miRNA sequences and validation in clinical samples.
Main Results:
- The developed biosensor achieved a low detection limit of 100 aM for miR-145.
- Demonstrated high specificity, distinguishing miRNAs with single-base differences.
- Successfully differentiated between healthy individuals and stroke patients, with results correlating with RT-qPCR.
Conclusions:
- The novel electrochemical biosensor offers a sensitive, specific, and reliable method for miR-145 detection.
- This technology holds significant potential for advancing stroke research and clinical diagnostics.
- The biosensor overcomes limitations of existing methods for detecting challenging biomarkers in complex matrices.
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