Biosensors & Bioelectronics

Real-time In-situ Detection of Microbes

Abstract

Linda S Powers, Walther R. Ellis and Christopher R. Lloyd

Currently, no methods exist for the real-time detection and quantification of microbes in the environment or for the detection and identification of pathogenic organisms in clinical specimens. We have developed technologies which overcome these limitations and provide detection limits as low as a ten microbial cells per cm2 on abiotic surfaces, and per mL in fluids. The detection and quantification of microbes [total microbial load] is based on the intrinsic fluorescence of microbial metabolites and protein cofactors, and provides an estimate of the total microbial load as well as the relative distribution of live cells, dead cells, and endospores. Unlike existing methods, no additional reagents or sample contact is needed. This technology has been applied to the in-situ measurements of two sub-glacial microbial communities at sites in the Svalbard Archipelago, Norway, and to the efficacy of disinfection of contact lenses. In the rapid spread of a life-threatening infection, early diagnosis is of great importance. In such situations, pathogen counts will be very low, which also presents a significant challenge to diagnostic methods. We have developed a point of care disposable diagnostic based on the en masse capture of blood-borne microbes from 1 mL of fresh whole blood with surface-tethered, small molecule ligands. Quantification is based on the intrinsic fluorescence of captured cells.