Electronic prototype delivers fault free fingerprint analysis

According to Intelligent Fingerprinting, a spin out of the University of East Anglia, the device can detect drugs and other substances from the sweat contained in fingerprints. It then carries out mobile testing and delivers instant results. The company has developed the prototype with Cambridge based design consultancy, eg technology. The device enables fingerprint testing using disposable cartridges, from which samples can be quickly collected. It does not require specialist handling or biohazard precautions and has an inbuilt watertight chain of evidence continuity. This process to detect drugs and metabolites in direct association with the sweat pores from within the fingerprint itself means that tests cannot give a false positive as a result of innocent contamination. Potential applications include criminal justice forensic science, homeland security and institutional testing such as prisons and workplaces. The key behind the process is the use of integrated coated nanoparticles. These are formed into antibody conjugates for the metabolite being detected in the fingerprint by binding antibodies to the nanoparticles using proteins and linker molecules. These are then used to bind target metabolites in the fingerprint. Firstly, the fingerprint is imaged using white oblique light, then treated by an aqueous solution of the nanoparticle antibody conjugates. Once this has been incubated for a few minutes, the antibodies bind with the metabolites in the fingerprint and excess unbound antibody conjugates are removed. Although it is possible to view the results of the analysis with white light, the fingerprint is further developed by the second application of a further antibody coupled to a fluorescent dye. According to the researchers, the quality of images that are revealed when the dye binds can be 'profound' and can be readily used to identify the owner of the mark through conventional comparison procedures. Of greater significance is that the images clearly show that the detected metabolites are first released from the individual sweat pores before spreading down the ridges to create the fingerprint image. It is this evidence linking the metabolite to the individual sweat pores that proves that the metabolite of the substance being detected was ingested by the owner of the fingerprint. By eliminating the possibility of contamination or secondary transfer, the researchers describe the technology as 'evidentially priceless' in many criminal investigations. Danny Godfrey, director of eg technology, said: "Intelligent Fingerprinting's core intellectual property is fascinating, offering a unique, robust way of linking a test result to the individual. Designing a device to automate their well defined laboratory process has required input from all of our skill groups – microfluidics, optics, electronics, software, industrial and mechanical design. The release of this prototype is a major milestone towards the unveiling of the production device next year and we're delighted to be part of such an exciting development."