A novel dual-mode aptasensor based colorimetry and electrochemical detection of norovirus in fecal sample

Electrochemical molecularly imprinted polymer sensors in viral diagnostics: Innovations, challenges and case studies

Molecularly imprinted polymers (MIPs) are synthetic equivalent of antibodies and have been widely used in electrochemical sensing as recognition elements. They offer advantages over traditional recognition elements such as antibodies, nucleic acids and aptamers due to their simple synthesis, lower production costs, greater chemical and physical stability, and robust performance in diverse environments. Improved detection techniques and combining MIPs with materials like metal nanoparticles, carbon nanotubes, aptamers, metal organic frameworks, quantum dots, and electrochemically active internal probes show increasing potential. These combinations could become a reliable method for detecting viruses quickly, with performance similar or better than standard techniques. In this review article we provide detailed case studies covering ten different viruses (Bean pod mottle virus, Dengue virus, Zika virus, Foot-and-mouth disease virus, Human papillomavirus, Hepatitis C virus, Human immunodeficiency virus, Influenza A virus, Norovirus, Severe acute respiratory syndrome coronavirus 2) and over forty specific examples. We summarize the recent advances in the development of electrochemical MIP-based sensors for the diagnostics of viral diseases and compare their performance. Additionally, challenges and future perspectives of MIPs as promising recognition elements are discussed.

Norovirus detection technologies: From conventional methods to innovative biosensors

The norovirus (NoV), known for its high contagion rate, is the leading cause of acute gastroenteritis. The development of a NoV vaccine is hindered by significant antigenic variation, lack of suitable models, unknown vaccine protection duration, limited human challenge studies, complex performance patterns, and the absence of a reliable in vitro cultivation system, making prevention, early detection, and control the only effective measures to mitigate outbreaks. This review aims to discuss about several norovirus biosensor for point-of-care analysis. Several innovative biosensors have been developed, including techniques such as electrochemical NoV biosensors, colorimetric NoV biosensors, fluorescence NoV biosensors, CRISPR-based NoV biosensors, and other NoV biosensors. These approaches have detected norovirus in biological samples with high sensitivity and specificity. This biosensing technique holds significant promise, not only in improving the speed and accuracy of diagnostic processes but also in strengthening the global response to norovirus infections, thereby underscoring its pivotal role in public health and disease prevention.

Viral diarrheas - newer advances in diagnosis and management

PURPOSE OF REVIEW

Viruses are the most common etiological agents of diarrhea in children. Despite rotavirus vaccine introduction, rotavirus remains as the leading cause of death globally, followed by norovirus, which represents a diagnostic challenge. Here, we describe new advances in the diagnosis and management of viral diarrheas.

RECENT FINDINGS

Although immunoassays are widely used for their fast turnaround time and low cost, molecular techniques have become the most reliable diagnostic method due to their high sensitivity and capacity to analyze multiple pathogens in gastrointestinal panels. Isothermal nucleic acid amplification assays (LAMP and RPA) are promising techniques since they do not require sophisticated equipment and can be used as point-of-care testing. CRISPR/Cas nucleic acid detection systems are new diagnostic methods with great potential. Several recent published articles describe the role of human intestinal enteroids to characterize norovirus infection, to test new drugs, and for vaccine development. The interaction between the human gut microbiota and gastrointestinal viral infections has been extensively reviewed and offers some innovative mechanisms for therapeutic and preventive measures.

SUMMARY

Although important advances have been made, more research is needed to address remaining challenges and further improve diagnostic capabilities and better management strategies for this critical infectious disease.

Dual-Mode Virus Detection: Combining Electrochemical and Fluorescence Modalities for Enhanced Sensitivity and Reliability

This study introduces a dual-mode biosensor specifically designed for the quantitative detection of viruses in rapid analysis. The biosensor is unique in its use of both optical (fluorescence) and electrochemical (impedance) detection methods using the same nanocomposites, providing a dual confirmation system for virus (norovirus-like particles) quantification. The system is based on using two antibody-conjugated nanocomposites: CdSeS quantum dots and Au-N,S-GQD nanocomposites. For optical detection, the principle relies on the fluorescence quenching of CdSeS by Au-N,S-GQD in a sandwich structure with the target. Conversely, electrochemical detection is based on the change in impedance caused by the formation of the same sandwich structure. The biosensor demonstrated exceptional sensitivity, capable of detecting norovirus at concentrations of as low as femtomolar in the electrochemical method and picomolar in the optical method. In the dual-responsive concentration range from 10-13 to 10-10 M, the sensor is highly sensitive in both methods, creating significant changes in fluorescence intensity and impedance in the presence of virus. Furthermore, the biosensor exhibits a high degree of specificity, with a negligible response to nontarget proteins, even within complex test solutions. This work represents a significant advancement in the field of biosensor technology, offering a fast, accurate, and reliable method for diagnosing viral infections and diseases.