Fluid-Screen uses a two-part process first to concentrate bacteria from a fluid sample and then to detect them directly. The filter unit concentrates bacteria, and the sensor unit identifies them. Both of these units together make up the sterile disposable Fluid-Screen chip.
Dielectrophoresis is a force that works on uncharged particles to manipulate their motion in an electric field. We have tuned our field to specifically attract bacteria to an electrode. When this happens, we get a concentrated bacterial sample on the filter unit. Next, we change the electric field to repel the bacteria from the electrode all at once so they can be transferred to the sensor unit.
The sensor unit uses specially designed antibody-functionalized nanowire sensors to detect bacteria directly. The nanowire sensors work like a standard glucose sensor, but with increased sensitivity and specificity to bacteria of interest. When bacteria bind to the sensor, the reader unit registers a change in voltage that depends on how many bacteria bind. The result is a report of both the number and type of bacteria present in the sample.
The process of sample concentration and bacterial detection together take only minutes to complete.