A microfluidic biosensor architecture for the rapid detection of COVID-19

Leveraging microfluidic confinement to boost assay sensitivity and selectivity

The native and tunable microscale fluid manipulation accessible within 3D-printed configurations can be a transformative tool in biosensing, promoting mass transport and sample mixing to boost assay performance. In this study, we demonstrate that channel height restrictions can support a 2000% acceleration in target recruitment kinetics, a notable 600% improvement in target response magnitude, and a 300% enhancement in assay selectivity within an entirely reagentless format that requires neither catalytic amplification nor the employment of specialized nanomaterials. This highly accessible experimental configuration supports robust target detection from serum at simple, untreated, and un-passivated sensor surfaces. The underlying operational principles have been elucidated through a combination of theoretical analysis and COMSOL simulation; the enhanced analyte flux leveraged by channel confinement is directly responsible for these effects, which also scale with both bioreceptor surface density and target binding affinity. The operational simplicity of this assay format with its resolved channel and flux promoted assay performance, holds significant value not only for biosensing but also for broader microfluidic-integrated applications, such as biosynthesis and catalysis.

Microfluidic biosensors: revolutionizing detection in DNA analysis, cellular analysis, and pathogen detection

Microfluidic chips have emerged as versatile and powerful tools that enable the precise manipulation of fluids and bioparticles at the microscale. Their impact on detection applications is profound, offering advantages such as miniaturization, enhanced sensitivity, multiplexing capability, and integrated functions. These chips can be customized for specific techniques, such as DNA analysis, immunoassays, chemical sensing, and cell-based assays. With a wide range of types available, including Lab-on-a-Chip, droplet-based, paper-based, electrochemical, optical, and magnetic chips, they find applications in diverse fields such as medical diagnostics, DNA analysis, cell analysis, food safety testing, environmental monitoring, and industrial processes. This powerful technology replicates laboratory capabilities on miniature chip-scale devices, resulting in time and cost savings while enabling portability and field-use capability. Its impact spans genetic analysis, proteomic analysis, cell culture, biosensors, pathogen detection, and point-of-care diagnostics, playing a pivotal role in advancing chemical and biological analysis. The overall aim of this review is to provide an overview of the development of microfluidic biochips for biological detection and discuss their various applications.

Nanotechnology-based theranostic and prophylactic approaches against SARS-CoV-2

SARS-CoV-2 (COVID-19) pandemic has been an unpredicted burden on global healthcare system by infecting over 700 million individuals, with approximately 6 million deaths worldwide. COVID-19 significantly impacted all sectors, but it very adversely affected the healthcare system. These effects were much more evident in the resource limited part of the world. Individuals with acute conditions were also severely impacted. Although classical COVID-19 diagnostics such as RT-PCR and rapid antibody testing have played a crucial role in reducing the spread of infection, these diagnostic techniques are associated with certain limitations. For instance, drawback of RT-PCR diagnostics is that due to degradation of viral RNA during shipping, it can give false negative results. Also, rapid antibody testing majorly depends on the phase of infection and cannot be performed on immune compromised individuals. These limitations in current diagnostic tools require the development of nanodiagnostic tools for early detection of COVID-19 infection. Therefore, the SARS-CoV-2 outbreak has necessitated the development of specific, responsive, accurate, rapid, low-cost, and simple-to-use diagnostic tools at point of care. In recent years, early detection has been a challenge for several health diseases that require prompt attention and treatment. Disease identification at an early stage, increased imaging of inner health issues, and ease of diagnostic processes have all been established using a new discipline of laboratory medicine called nanodiagnostics, even before symptoms have appeared. Nanodiagnostics refers to the application of nanoparticles (material with size equal to or less than 100 nm) for medical diagnostic purposes. The special property of nanomaterials compared to their macroscopic counterparts is a lesser signal loss and an enhanced electromagnetic field. Nanosize of the detection material also enhances its sensitivity and increases the signal to noise ratio. Microchips, nanorobots, biosensors, nanoidentification of single-celled structures, and microelectromechanical systems are some of the most modern nanodiagnostics technologies now in development. Here, we have highlighted the important roles of nanotechnology in healthcare sector, with a detailed focus on the management of the COVID-19 pandemic. We outline the different types of nanotechnology-based diagnostic devices for SARS-CoV-2 and the possible applications of nanomaterials in COVID-19 treatment. We also discuss the utility of nanomaterials in formulating preventive strategies against SARS-CoV-2 including their use in manufacture of protective equipment, formulation of vaccines, and strategies for directly hindering viral infection. We further discuss the factors hindering the large-scale accessibility of nanotechnology-based healthcare applications and suggestions for overcoming them.

Microfluidics: a concise review of the history, principles, design, applications, and future outlook

Microfluidic technologies have garnered significant attention due to their ability to rapidly process samples and precisely manipulate fluids in assays, making them an attractive alternative to conventional experimental methods. With the potential for revolutionary capabilities in the future, this concise review provides readers with insights into the fascinating world of microfluidics. It begins by introducing the subject's historical background, allowing readers to familiarize themselves with the basics. The review then delves into the fundamental principles, discussing the underlying phenomena at play. Additionally, it highlights the different aspects of microfluidic device design, classification, and fabrication. Furthermore, the paper explores various applications, the global market, recent advancements, and challenges in the field. Finally, the review presents a positive outlook on trends and draws lessons to support the future flourishing of microfluidic technologies.