Sensitivity Of Lateral Flow Immunoassay Research Articles

Significantly Improved Analytical Sensitivity of Lateral Flow Immunoassays by Using Thermal Contrast

Heat beyond visual: The thermal contrast from the heating of gold nanoparticles upon laser stimulation can improve the analytical sensitivity of lateral flow assays (LFAs; see picture). A 32-fold improvement in sensitivity of an approved LFA for cryptococcal antigen (purple diamond) was shown, with the potential for further improvement by optimizing the backing material and the properties of the antibody-coated nanoparticles (red circle with blue Y).

Significantly Improved Analytical Sensitivity of Lateral Flow Immunoassays by Using Thermal Contrast

Significantly Improved Analytical Sensitivity of Lateral Flow Immunoassays by Using Thermal Contrast

Enhancing the lateral-flow immunoassay for viral detection using an aqueous two-phase micellar system.

Availability of a rapid, accurate, and reliable point-of-care (POC) device for detection of infectious agents and pandemic pathogens, such as swine-origin influenza A (H1N1) virus, is crucial for effective patient management and outbreak prevention. Due to its ease of use, rapid processing, and minimal power and laboratory equipment requirements, the lateral-flow (immuno)assay (LFA) has gained much attention in recent years as a possible solution. However, since the sensitivity of LFA has been shown to be inferior to that of the gold standards of pathogen detection, namely cell culture and real-time PCR, LFA remains an ineffective POC assay for preventing pandemic outbreaks. A practical solution for increasing the sensitivity of LFA is to concentrate the target agent in a solution prior to the detection step. In this study, an aqueous two-phase micellar system comprised of the nonionic surfactant Triton X-114 was investigated for concentrating a model virus, namely bacteriophage M13 (M13), prior to LFA. The volume ratio of the two coexisting micellar phases was manipulated to concentrate M13 in the top, micelle-poor phase. The concentration step effectively improved the M13 detection limit of the assay by tenfold from 5 × 108 plaque forming units (pfu)/mL to 5 × 107 pfu/mL. In the future, the volume ratio can be further manipulated to yield a greater concentration of a target virus and further decrease the detection limits of the LFA. FigureA schematic representation of concentrating viruses with an aqueous two-phase micellar system containing Triton X-114 surfactant prior to the detection of the virus through the lateral-flow immunoassay Electronic supplementary materialThe online version of this article (doi:10.1007/s00216-010-4213-7) contains supplementary material, which is available to authorized users.