Researchers at the University of Twente have developed a sensor capable of detecting anthrax at concentrations 1,000 lower than the known minimum infective dose of the spores. The reusable system is reportedly much more effective than fluorescence and mass spectroscopy while not needing any calibration prior to taking readings.
Like other detection techniques, the UT sensor measures the presence of dipicolinic acid (DPA), a substance that accounts for between five and fifteen per cent of the dry weight of the spores. The sensor consists of a glass plate to which DPA-sensitive receptors have been attached. When the receptors are brought into contact with anthrax spores, the DPA binds with them. The concentration of the spores can be calculated with fluorescence spectroscopy, by shining ultraviolet light on to the sensor. DPA-bonded receptors will absorb this light and emit blue light, whereas receptors that have no DPA bonding will emit red light. By measuring the ratio of red to blue light in a sample, it is possible to determine the concentration of anthrax spores. The advantage of the sensor is that it does not need calibrating and is more finely tuned than other current methods. The next step for the researchers is to convert the system into a ‘lab-on-a-chip’ which will make it possible to measure samples using a fully automatic on-off process.
Press release: UT researchers develop anthrax sensor …
Abstract in Angewandte Chemie International Edition: Ratiometric Fluorescent Detection of an Anthrax Biomarker at Molecular Printboards
