Researchers further develop rapid response biosensor to detect food-borne pathogens

摘要

The USA's Georgia Tech's biosensor development team is making good progress in its efforts to design a practical and innovative tool for detecting pathogens in poultry processing. The development effort is now entering a critical phase with researchers both enhancing the sensitivity of the biosensor and engineering a field-usable instrument. The biosensor technology uses a planar optical waveguide with interferometric detection methods for selective and quantitative measurement of micro-organisms.It is a relatively simple device and consists of four basic components: a glass waveguide functionalised with specific antibodies; a small, low-power diode laser as a light source; a charge-coupled device (CCD) detector; and associated electronics for signal acquisition and processing. A recent enhancement to the design has been in optimising the immunoassay protocol to allow for a conceptually simple, rapid and inexpensive assay method. There are two general methods of waveguide immunoassay detection.A direct detection scheme couples the capture antibody on the surface of the sensor. An indirect detection scheme uses enzyme-labelled antibodies in a sandwich immunoassay that produces a product that is measured by the sensor. After spending more than ayear evaluating the indirect method, researchers switched to the direct approach to speed up detection - crucial for its practical use in process control.