In a new study, researchers demonstrate the capability of DNA biosensor components for a unique modular DNA biosensor. The researchers plan to integrate their design within a device the size and shape of a smartphone for low-cost clinical diagnostics. (Credit: N. Hanacek/NIST)

A new biosensor chip that boasts an accurate and inexpensive design may increase accessibility to high-quality diagnostics. The biosensor identifies biomarkers by measuring how binding occurs between DNA strands and the device. What sets it apart from other similar sensors is its modular design, which lowers costs by making it easier to mass produce and by allowing the most expensive components to be reused.

Like other DNA biosensors, the device takes advantage of the fact that a single DNA strand, when not paired with another within the familiar double helix, is primed for chemical bonding. Part of the device is coated with single strands of DNA. When these probes encounter DNA biomarkers that have a corresponding, or complementary, genetic sequence, the two strands bind, sending a signal that is picked up by the device.

To test the performance of their device, they placed it in liquid samples containing DNA strands associated with exposure to harmful ionizing radiation. Complementary DNA probes adorned electrodes wired to the FET. Across several samples, they varied the amount of target DNA.

The researchers found that the binding kinetics were sensitive enough to make accurate measurements even at low concentrations. Overall, the performance of the modular design matched that of integrated, nonmodular FET-based biosensors.