Facile and foldable point-of-care biochip for nucleic acid based-colorimetric detection of murine norovirus in fecal samples using G-quadruplex and graphene oxide coated microbeads

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.

Pathogen detection via inductively coupled plasma mass spectrometry analysis with nanoparticles

Infections caused by viruses and bacteria pose a significant threat to global public health, emphasizing the critical importance of timely and precise detection methods. Inductively coupled plasma mass spectrometry (ICP-MS), a contemporary approach for pathogen detection, offers distinct advantages such as high sensitivity, a wide linear range, and multi-index capabilities. This review elucidates the underexplored application of ICP-MS in conjunction with functional nanoparticles (NPs) for the identification of viruses and bacteria. The review commences with an elucidation of the underlying principles, procedures, target pathogens, and NP requirements for this innovative approach. Subsequently, a thorough analysis of the advantages and limitations associated with these techniques is provided. Furthermore, the review delves into a comprehensive examination of the challenges encountered when utilizing NPs and ICP-MS for pathogen detection, culminating in a forward-looking assessment of the potential pathways for advancement in this domain. Thus, this review contributes novel perspectives to the field of pathogen detection in biomedicine by showcasing the promising synergy of ICP-MS and NPs.

Flexible/Regenerative Nanosensor with Automatic Sweat Collection for Cytokine Storm Biomarker Detection

The real-time monitoring of low-concentration cytokines such as TNF-α in sweat can aid clinical physicians in assessing the severity of inflammation. The challenges associated with the collection and the presence of impurities can significantly impede the detection of proteins in sweat. This issue is addressed by incorporating a nanosphere array designed for automatic sweat transportation, coupled with a reusable sensor that employs a Nafion/aptamer-modified MoS2 field-effect transistor. The nanosphere array with stepwise wettability enables automatic collection of sweat and blocks impurities from contaminating the detection zone. This device enables direct detection of TNF-α proteins in undiluted sweat, within a detection range of 10 fM to 1 nM. The use of an ultrathin, ultraflexible substrate ensures stable electrical performance, even after up to 30 extreme deformations. The findings indicate that in clinical scenarios, this device could potentially provide real-time evaluation and management of patients' immune status via sweat testing.

Self-Powered Immunoassay of Norovirus in Human Stools by π-Electron-Rich Homojunction for Enhanced Charge Transfer

Norovirus (NoV) stands as a significant causative agent of nonbacterial acute gastroenteritis on a global scale, presenting a substantial threat to public health. Hence, the development of simple and rapid analytical techniques for NoV detection holds great importance in preventing and controlling the outbreak of the epidemic. In this work, a self-powered photoelectrochemical (PEC) immunosensor of NoV capsid protein (VP1) was proposed by the π-electron-rich carbon nitride homojunction (ER-CNH) as the photoanode. C4N2 ring derived from π-rich locust bean gum was introduced into the tri-s-triazine structure, creating a large π-delocalized conjugated carbon nitride homojunction. This strategy enhances the C/N atomic ratio, which widens light utilization, narrows the bandgap, and optimizes the electronic band structure of carbon nitride. By introduction of a π-rich conjugated structure, p-type domains were induced within n-type domains to build the internal electric field at the interface, thus forming a p-n homojunction to boost carrier separation and transfer. The ER-CNH photoanode exhibited excellent photoelectric performance and water oxidation capacity. Since VP1 inhibits the water oxidation of the ER-CNH photoanode, the open-circuit potential of the as-prepared PEC immunosensor system was reduced for detecting NoV VP1. The self-powered PEC immunosensor achieved a remarkably low detection limit (∼5 fg mL-1) and displayed high stability and applicability for actual stool samples. This research serves as a foundation concept for constructing immunosensors to detect other viruses and promotes the application of self-powered systems for life safety.

Microfluidic systems for infectious disease diagnostics

Microorganisms, encompassing both uni- and multicellular entities, exhibit remarkable diversity as omnipresent life forms in nature. They play a pivotal role by supplying essential components for sustaining biological processes across diverse ecosystems, including higher host organisms. The complex interactions within the human gut microbiota are crucial for metabolic functions, immune responses, and biochemical signalling, particularly through the gut-brain axis. Viruses also play important roles in biological processes, for example by increasing genetic diversity through horizontal gene transfer when replicating inside living cells. On the other hand, infection of the human body by microbiological agents may lead to severe physiological disorders and diseases. Infectious diseases pose a significant burden on global healthcare systems, characterized by substantial variations in the epidemiological landscape. Fast spreading antibiotic resistance or uncontrolled outbreaks of communicable diseases are major challenges at present. Furthermore, delivering field-proven point-of-care diagnostic tools to the most severely affected populations in low-resource settings is particularly important and challenging. New paradigms and technological approaches enabling rapid and informed disease management need to be implemented. In this respect, infectious disease diagnostics taking advantage of microfluidic systems combined with integrated biosensor-based pathogen detection offers a host of innovative and promising solutions. In this review, we aim to outline recent activities and progress in the development of microfluidic diagnostic tools. Our literature research mainly covers the last 5 years. We will follow a classification scheme based on the human body systems primarily involved at the clinical level or on specific pathogen transmission modes. Important diseases, such as tuberculosis and malaria, will be addressed more extensively.

Advances in nanobiosensors during the COVID-19 pandemic and future perspectives for the post-COVID era

The unprecedented threat of the highly contagious virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes exponentially increased infections of coronavirus disease 2019 (COVID-19), highlights the weak spots of the current diagnostic toolbox. In the midst of catastrophe, nanobiosensors offer a new opportunity as an alternative tool to fill a gap among molecular tests, rapid antigen tests, and serological tests. Nanobiosensors surpass the potential of antigen tests because of their enhanced sensitivity, thus enabling us to see antigens as stable and easy-to-access targets. During the first three years of the COVID-19 pandemic, a substantial number of studies have reported nanobiosensors for the detection of SARS-CoV-2 antigens. The number of articles on nanobiosensors and SARS-CoV-2 exceeds the amount of nanobiosensor research on detecting previous infectious diseases, from influenza to SARS-CoV and MERS-CoV. This unprecedented publishing pace also implies the significance of SARS-CoV-2 and the present pandemic. In this review, 158 studies reporting nanobiosensors for detecting SARS-CoV-2 antigens are collected to discuss the current challenges of nanobiosensors using the criteria of point-of-care (POC) diagnostics along with COVID-specific issues. These advances and lessons during the pandemic pave the way for preparing for the post-COVID era and potential upcoming infectious diseases.

Graphene oxide-enhanced colorimetric detection of Mec A gene based on toehold-mediated strand displacement

Mec A, as a representative gene mediating resistance to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA), allows a new genetic analysis for the detection of MRSA. Here, a sensitive, prompt, and visual colorimetry is reported to detect the Mec A gene based on toehold-mediated strand displacement (TMSD) and the enrichment effect of graphene oxide (GO). The Mec A triggers to generate the profuse amount of signal units of single-stranded DNA (SG) composed of a long single-stranded base tail and a base head: the tail can be adsorbed and enriched on the surface of GO; the head can form a G quadruplex structure to exert catalytic function towards 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid). Therefore, through the enrichment effect of GO, the signal units SG reflects different degrees of signal amplification on different substrates (such as aqueous solution or filter membrane). This strategy demonstrates a broad linear working range from 100 pM to 1.5 nM (solution) and 1 pM to 1 nM (filter membrane), with a low detection limit of 39.53 pM (solution) and 333 fM (filter membrane). Analytical performance in real samples suggests that this developed colorimetry is endowed with immense potential for clinical detection applications.

Nanoparticles-assisted aptamer biosensing for the detection of environmental pathogens

Given the importance of public health, it is crucial to develop quick, targeted, highly sensitive, and accurate technologies to monitor pathogenic microbes in response to the growing concerns of food and environmental safety. Although conventional approaches for microbiological detection are available, they are laborious, and often skill demanding. Therefore, such approaches are incompetent in the on-site or high-throughput assessment of pathogenic microbes. Numerous efforts have been made to develop biosensors that use nucleic acid aptamer as the biorecognition element, which would avoid the abovementioned limitations. Incorporating nanomaterials (NMs) into aptamer-based biosensors (aptasensors) improves their sensitivity and specificity, opening exciting possibilities for various applications, such as bioanalysis of food and environmental samples. Over the last decade, nanomaterial-conjugated aptasensors have seen a steadily rising demand. To this end, the main goal of this study is to demonstrate the novelty in the design of nanomaterial-conjugated aptasensors and how they can be used to detect different pathogenic microbes in water and food. The intent of this paper is to evaluate the cutting-edge techniques that have appeared in nano-aptasensors throughout the past few years, such as manufacturing procedures, analytical credibility, and sensing mechanisms. Additionally, the fundamental performance parameters of aptasensing techniques (such as detection limits, and sensing ranges response) were also used to evaluate their practical applicability. Finally, it is anticipated that this study will inspire innovative ideas and techniques for the construction and use of aptasensors for monitoring pathogenic microorganisms in food, drinks, recreational water, and wastewater.

Human Norovirus Detection: How Much Are We Prepared?

Norovirus (NoV) is known to be the second nonbacterial enteric pathogen after rotavirus that causes acute gastroenteritis. They can be spread from person to person through fecal-oral routes. Infection can lead to severe diarrhea, causing stomach pain, vomiting, and nausea. Rapid detection of NoV can control huge economic and productive losses. Genotyping various emerging NoV strains is important to compare the severity among different strains. Conventional immunological and molecular methods have evolved and contributed to developing detection techniques. Immunological (enzyme-linked immunosorbent assay) and molecular detection (reverse transcriptase polymerase chain reaction [RT-PCR], RT-quantitative PCR, loop-mediated isothermal amplification, nucleic acid sequence-based alignment, recombinase polymerase amplification) methods have been mainly used. The development of biosensors using aptasensor, affinity peptides, nanoparticles, microfluidics, and so on, are currently the most researched topics. The availability of next-generation sequencing technologies has greatly influenced the diagnosis of NoV. The complementation of advanced technologies is helpful in identification of new variants. In this study, techniques that are useful in detecting NoV are discussed. This review has investigated the availability of recent methods used in the detection, present status, and futuristic plan of action in case of outbreak and pandemic.

Biosensors for waterborne virus detection: Challenges and strategies

Waterborne viruses that can be harmful to human health pose significant challenges globally, affecting health care systems and the economy. Identifying these waterborne pathogens is essential for preventing diseases and protecting public health. However, handling complex samples such as human and wastewater can be challenging due to their dynamic and complex composition and the ultralow concentration of target analytes. This review presents a comprehensive overview of the latest breakthroughs in waterborne virus biosensors. It begins by highlighting several promising strategies that enhance the sensing performance of optical and electrochemical biosensors in human samples. These strategies include optimizing bioreceptor selection, transduction elements, signal amplification, and integrated sensing systems. Furthermore, the insights gained from biosensing waterborne viruses in human samples are applied to improve biosensing in wastewater, with a particular focus on sampling and sample pretreatment due to the dispersion characteristics of waterborne viruses in wastewater. This review suggests that implementing a comprehensive system that integrates the entire waterborne virus detection process with high-accuracy analysis could enhance virus monitoring. These findings provide valuable insights for improving the effectiveness of waterborne virus detection, which could have significant implications for public health and environmental management.

Advances in Simple, Rapid, and Contamination-Free Instantaneous Nucleic Acid Devices for Pathogen Detection

Pathogenic pathogens invade the human body through various pathways, causing damage to host cells, tissues, and their functions, ultimately leading to the development of diseases and posing a threat to human health. The rapid and accurate detection of pathogenic pathogens in humans is crucial and pressing. Nucleic acid detection offers advantages such as higher sensitivity, accuracy, and specificity compared to antibody and antigen detection methods. However, conventional nucleic acid testing is time-consuming, labor-intensive, and requires sophisticated equipment and specialized medical personnel. Therefore, this review focuses on advanced nucleic acid testing systems that aim to address the issues of testing time, portability, degree of automation, and cross-contamination. These systems include extraction-free rapid nucleic acid testing, fully automated extraction, amplification, and detection, as well as fully enclosed testing and commercial nucleic acid testing equipment. Additionally, the biochemical methods used for extraction, amplification, and detection in nucleic acid testing are briefly described. We hope that this review will inspire further research and the development of more suitable extraction-free reagents and fully automated testing devices for rapid, point-of-care diagnostics.

Detection Methods for Foodborne Viruses: Current State-of-Art and Future Perspectives

Foodborne viruses have been recognized as important threats to food safety and human health. Rapid and accurate detection is one of the most crucial measures for food safety control. With the development of biology, chemistry, nanoscience, and related interdisciplines, detection strategies have been devised and advanced continuously. This review mainly focuses on the progress of detection methods for foodborne viruses. The current detection methods for foodborne viruses are summarized, including traditional electron microscopy and cultural isolation, immunoassay, molecular technology, biosensors, and newly emerging CRISPR/Cas-based detection technology. Furthermore, a comparison of the detection methods was objectively discussed. This review provides a comprehensive account of foodborne virus detection methods from fundamentals to state-of-the-art and illustrates the advantages and disadvantages of the current methods and proposes the future trends and directions for foodborne virus detection. It is hoped that this review can update current knowledge and present blueprints in order to accelerate futuristic development.