BiodefenseInnovative biosensor for rapid virus field tests

Published 8 August 2011

Relying on a novel DNA-based bio-chemo-physical conversion method, a new bio-detection device is able to detect harmful bacteria, such as E. coli, salmonella, and staphylococcus, on site, within thirty minutes; it can be adapted to cover such deadly viruses as SARS, H5N1 flu, and swine flu viruses; it can also be designed to monitor possible biological attack from anthrax, smallpox, cholera, and more

Two researchers at the Hong Kong Polytechnic University — Professor Samuel Lo, Associate Head of the Department of Applied Biology and Chemical Technology, and Dr. Derek Or, Associate Professor of the Department of Electrical Engineering — have jointly developed a Portable Real-time DNA< Biosensor.

The device is designed to perform speedy in situ DNA tests for biodefense and health surveillance purposes in areas suspected to be contaminated with pathogens and/or undesirable microbes.

A Hong Kong Polytechnic University release reports that unlike conventional laboratory tests that take at least one or two days, this hand-held, battery-operated and fully automated biosensor is built upon a novel DNA-based bio-chemo-physical conversion method. It is able to detect harmful bacteria, such as E. coli, salmonella, and staphylococcus, on site, within thirty minutes. It can be adapted to cover such deadly viruses as SARS, H5N1 flu, and swine flu viruses. It can also be re-designed to monitor possible biological attack from anthrax, smallpox, and cholera etc.

Comprising a reaction chamber, an ultrasound core, and an electronics power board, the new biosensor can test for the presence of a specific pathogen in water and air samples by recognizing the existence of its DNA. When this pathogen is added to the reaction chamber, the further addition of both specific primer-linked thrombin and fibrinogen triggers an innovative molecular bio-chemical reaction. In the case of a DNA primer match, the enzyme will convert fibrinogen into a lump of visible gel that blocks the transmission of ultrasound signals through the reaction chamber. A drop in the ultrasound reading is then a strong indicator of the presence of the target pathogen in the sample.

This invention won a Gold Award at the 39th International Exhibition of Inventions in Geneva, Switzerland.