Currently there is no simple and easy way to detect infectious bacteria at either farms or in the food processing and distribution plants. This even extends to some of the most commonly occurring food-borne diseases such as campylobacter and salmonella. For a simple test to take place, samples have to be taken and sent to labs, a process that can take hours or days.
OptoLabCard project however has created one of only two prototype systems in the world that prepares samples and performs DNA tests on bacteria in a portable, easy-to-use and cost-effective chip. This innovative prototype promises to carry out tests in as little as half an hour. Such an impressive turnaround time combined with low costs would drastically improve the safety of food.
The idea of a small handheld device capable of performing tests usually carried out in a full-sized laboratory has been around for a long time. It has only been since the arrival of microelectromechanical systems (mems) technology that it is possible to put sensors, fluid channels and optical components into a small space.
Essentially the prototype device consists of a handheld base unit and a cartridge or ‘labcard’ that will carry out a real time polymerase chain reaction automatically, from sample preparation to an optical detection. The labcard is made from a light sensitive material called SU-8, and contains all the disposable components, whereas the base unit includes all the standard electronics and optics.
The range of applications of such a device is virtually limitless and can be applied to areas outside of food safety and the detection of salmonella or campylobacter. It can be used to detect other infectious diseases, flu in humans, tuberculosis, hepatitis, AIDS, and even to detect cancer in clinical samples. Their prototype could also be used to develop portable devices that can identify pathogens and pollution in water supplies.
What sets the OptoLabCard prototype apart from other devices is its cost-effectiveness. The use of a single material, SU-8, in the manufacture of most of its components makes the chips simpler and cheaper to produce. The chip itself is disposable, while a reader or base unit contains all the electronics and optics. Meanwhile, incorporating sample preparation into the chip means that users can effectively replicate laboratory processes out in the field.
The OptoLabCard consortium consists of nine Government Research Institutions (RES), Industrial companies (IND), and universities originated from six EU countries (Denmark, Sweden, Poland, Austria, Germany and Spain).
A spin-off company, called microLIQUID has been set up to commercialise components built with SU-8, while several of the project partners have recently launched a new project, called LabOnFoil, in which they will seek to create sample processing and detection chips on foils instead of traditional silicon wafers.