Dual Capability Time-resolved Fluorescence and Colourimetric Based Lateral Flow Reader for High Sensitivity Diagnostics Applications

"Lateral flow assays (LFA) are diagnostics tests where a liquid sample is applied to a small nitrocellulose membrane pre-patterned with reagents for detection of particular proteins, cells, chemical molecules or microorganisms. The existing market is worth circa $5.5bn per annum (Source: MarketsandMarkets 2017 Lateral Flow Assay Market Report) with LFAs used for numerous applications including human diagnostics (e.g. infectious disease, drugs of abuse), animal health, agricultural, food monitoring and environmental testing. Most of the existing tests, such as pregnancy tests, are based on the presence or absence of coloured lines generating a positive or a negative test result.

For many applications this qualitative result is sufficient and in fact the application of LFAs is largely limited to qualitative or semi-quantitative tests. However, there are many other uses when determining how much of the analyte is present is required. For example: in human health, testing of cardiac markers; in animal health, the use of antibiotics in animals; in agriculture, mycotoxins in food. There is a significant requirement for laboratory-standard quantitative LFA results in a point of contact (POC) environment and in particular a LFA reader system that allows quantification with very high sensitivity.

Our vision is to develop and launch a highly flexible, cost-effective, leading-edge lateral flow reader platform that delivers laboratory standard test results in a POC environment. Time resolved fluorescence detection (TRFL) technology has the potential to revolutionise diagnostic testing across a range of areas including the clinical, animal health, environmental and agri-tech testing markets through enabling a paradigm shift to higher sensitivity LFAs. Our objective is to test the feasibility of a novel lateral flow test reader which can read both colourimetric and fluorescence, specifically TRFL, based tests in a single desktop instrument that is suitable for use in a variety of settings including GP surgeries, veterinary clinics and farms. Our technique will use long-life Europium based fluorophores to highlight the analyte. Using the long decay time property of this label, we will design a novel system which isolates our signal of interest from the background noise by separating them in time by a time-gated technique. To our knowledge there are no LFA readers supporting simultaneous dual-signal-detection technology commercially available or in development. This innovation provides cost-effectiveness by enabling quantification of analytes previously unmeasurable on a compact, desktop system as well as allowing one reader to be used to measure different LFA types."