Dengue virus (DENV), a member of the Flavivirus genus, poses a significant global health challenge due to its widespread transmission by Aedes mosquitoes and the lack of effective therapeutics. With an estimated 390 million infections annually and nearly 4 billion people at risk, early and accurate diagnosis is essential for timely intervention and outbreak control. Traditional diagnostic methods such as virus isolation and nucleic acid amplification are resource-intensive and time-consuming, while serological assays like MAC-ELISA suffer from poor sensitivity and cross-reactivity with other flaviviruses. The development of rapid, sensitive, and specific point-of-care diagnostics remains a critical need, particularly in endemic regions with limited infrastructure.
This study presents a novel electrochemical immunosensor based on graphene-coated screen-printed carbon electrodes (SPCEs) for the detection of dengue-specific IgG antibodies. The key innovation lies in the use of a consensus envelope glycoprotein domain III (cEDIII) derived from Nicotiana benthamiana plants as the antigenic probe. cEDIII is highly conserved across all four DENV serotypes and has demonstrated superior specificity compared to conventional NS1-based assays. The plant-based expression system offers scalable, cost-effective, and safe production without the need for animal-derived materials or complex microbial cultures.CTTN Antibody medchemexpress
The fabrication process began with the synthesis of pristine graphene via sono-assisted liquid phase exfoliation, followed by functionalization with 1-pyrenebutyric acid N-hydroxysuccinimide ester (PSE), which serves as a bi-linker for covalent immobilization of cEDIII onto the electrode surface.BACE Antibody site Electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the successful construction of the sensing platform, with a significant increase in charge transfer resistance (Rct) following each modification step.PMID:34029174 The optimal graphene mass loading was determined to be 31.83 g cm⁻² (G04), exhibiting the lowest Rct and highest electron transfer efficiency.
Under optimized conditions, the immunosensor displayed a wide linear response range from 125 to 2000 ng mL⁻¹ for DENV IgG, with a remarkably low limit of detection (LOD) of 22.5 ng mL⁻¹. This performance surpasses many existing biosensors reported in the literature. The sensor demonstrated high specificity, showing minimal response to antibodies against Zika virus (ZIKV), avian influenza (H5N1), infectious bursal disease virus (IBDV), and chicken anaemia virus (CAV), despite ZIKV’s structural similarity to DENV. This ability to differentiate closely related flaviviruses highlights its potential for reducing false positives in clinical settings.
Preliminary validation using mouse serum samples further confirmed the practical applicability of the sensor. The blank serum (G1) showed a relative Rct value of 72.8%, indicating baseline non-specific binding, while the immunized serum (G2) yielded a significantly higher response of 133.3%. This binary (positive/negative) output was comparable to results obtained from in-house ELISA, confirming the sensor’s reliability in real biological matrices. Notably, the assay required only 60 minutes of target hybridization and avoided secondary antibody labeling, enabling rapid, low-cost testing with reduced background noise.
In summary, this graphene-based immunosensor integrates advanced nanomaterials with plant-derived antigens to deliver a sensitive, specific, and robust platform for dengue detection. Its simplicity, fast turnaround, and compatibility with portable devices make it a promising candidate for point-of-care applications in resource-limited environments. Future work will focus on multiplexing capabilities and integration into handheld diagnostic platforms to support real-time surveillance during outbreaks.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
