A regenerable flow-through affinity sensor for label-free detection of proteins and DNA

Development and Bioanalytical Applications of a White Light Reflectance Spectroscopy Label-Free Sensing Platform

The development of a sensing platform based on white light reflectance spectroscopy (WLRS) is presented. The evolution of the system, from polymer film characterization and sensing of volatile organic compounds to biosensor for the label-free determination of either high (e.g., proteins) or low molecular weight analytes (e.g., pesticides), is described. At the same time, the passage from single to multi-analyte determinations, and from a laboratory prototype set-up to a compact device appropriate for on-site determination, is outlined. The improvements made on both the sensor and the optical set-up, and the concomitant advances in the analytical characteristics and the robustness of the assays performed with the different layouts, are also presented. Finally, the future perspectives of the system, aiming for the creation of a standalone instrument to be used by non-experts, will be discussed.

Optic fiber-based immunosensor for the rapid and sensitive detection of hepatitis C virus in serum

A portable optic fiber-based immunosensor is developed to achieve rapid and sensitive hepatitis C virus detection in serum.

Discerning Trends in Multiplex Immunoassay Technology with Potential for Resource-Limited Settings

BACKGROUND

In the search for more powerful tools for diagnoses of endemic diseases in resource-limited settings, we have been analyzing technologies with potential applicability. Increasingly, the process focuses on readily accessible bodily fluids combined with increasingly powerful multiplex capabilities to unambiguously diagnose a condition without resorting to reliance on a sophisticated reference laboratory. Although these technological advances may well have important implications for the sensitive and specific detection of disease, to date their clinical utility has not been demonstrated, especially in resource-limited settings. Furthermore, many emerging technological developments are in fields of physics or engineering, which are not readily available to or intelligible to clinicians or clinical laboratory scientists.

CONTENT

This review provides a look at technology trends that could have applicability to high-sensitivity multiplexed immunoassays in resource-limited settings. Various technologies are explained and assessed according to potential for reaching relevant limits of cost, sensitivity, and multiplex capability. Frequently, such work is reported in technical journals not normally read by clinical scientists, and the authors make enthusiastic claims for the potential of their technology while ignoring potential pitfalls. Thus it is important to draw attention to technical hurdles that authors may not be publicizing.

SUMMARY

Immunochromatographic assays, optical methods including those involving waveguides, electrochemical methods, magnetorestrictive methods, and field-effect transistor methods based on nanotubes, nanowires, and nanoribbons reveal possibilities as next-generation technologies.