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Published on: June 1, 2011
Highly sensitive and specific electrochemical biosensor for direct detection of hepatitis C virus RNA in clinical
Thanyarat Chaibun1, Sinthu Karunaithas1, Tatchanun Ngamdee2
1Biosensors Laboratory, Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom, Thailand.
Insights
A new electrochemical biosensor offers rapid, low-cost point-of-care testing for Hepatitis C virus (HCV) RNA. This innovation aids early diagnosis and prevention, especially in resource-limited areas lacking advanced molecular diagnostics.
Area of Science:
- Biomedical Engineering
- Molecular Diagnostics
- Infectious Disease Detection
Background:
- Hepatitis C virus (HCV) infection poses significant global health risks, including liver cirrhosis and hepatocellular cancer.
- Effective management relies on early diagnosis, yet current molecular diagnostic tools are costly and complex, limiting accessibility.
- No vaccine exists for HCV prevention, underscoring the need for accessible diagnostic solutions.
Purpose of the Study:
- To develop a novel electrochemical biosensor for rapid, point-of-care detection of Hepatitis C virus RNA.
- To overcome the limitations of existing diagnostic methods in terms of cost, complexity, and accessibility.
Main Methods:
- A novel electrochemical biosensor employing a strand displacement mechanism was developed.
- The sensor uses gold nanoparticle-labeled reporter probes (AuRP) and magnetic nanoparticle-labeled capture probes.
- Detection of displaced AuRP was performed using differential pulse anodic stripping voltammetry (DPASV).
Main Results:
- The biosensor demonstrated high sensitivity with a detection limit of 4 fM for synthetic targets.
- It successfully detected Hepatitis C virus RNA directly in clinical plasma samples without prior RNA extraction or amplification.
- Results showed good concordance with established RT-PCR methods when analyzing clinical samples.
Conclusions:
- The developed electrochemical biosensor is a promising tool for point-of-care testing of Hepatitis C virus RNA.
- This technology has the potential to significantly improve early diagnosis and management of HCV infections, particularly in resource-limited settings.
- The sensor's direct detection capability and high performance offer a viable alternative to complex molecular diagnostic techniques.
Abstract:
Hepatitis C virus (HCV) is a common blood-borne infection that can lead to long-term illnesses such as hepatocellular cancer and liver cirrhosis. Early diagnosis is crucial for effective management, as no vaccine is available for preventing HCV infection. However, the high cost and complexity of current molecular diagnostic tools hinder efforts to achieve early diagnosis and prevent transmission, particularly in resource-limited settings. We developed a novel electrochemical biosensor for point-of-care testing (POCT) of HCV RNA. The sensor utilizes a strand displacement method, where the target RNA displaces a gold nanoparticle-labeled reporter probe (AuRP) from a pre-hybridized duplex with a magnetic nanoparticle (MNP)-labeled capture probe. The amount of displaced AuRP, detected using differential pulse anodic stripping voltammetry (DPASV), is directly proportional to the target RNA concentration. The biosensor exhibited excellent analytical performance, with a detection limit of 4 fM for synthetic targets and 43 ng/µL for RT-PCR products. Importantly, it successfully detected HCV RNA directly in clinical plasma samples without the need for RNA extraction or amplification. The sensor was used to analyze 30 RNA samples from HCV-positive patients, 20 cDNA samples from viral RNA, 30 HCV-positive plasma samples, and 22 HCV-negative plasma samples. The sensor results show good concordance with the RT-PCR results, demonstrating the sensor's potential for detecting HCV in clinical samples.
