Sensor-on-a-Chip, Linked to a Microcontroller, Can Track Disease Severity From a Small Blood Sample

Researchers at Hokkaido University, Tokushima University, and Nagoya University have demonstrated a prototype biosensor that, they say, could track the severity of several diseases from a small sample of blood.

"In 2013, our co-authors at Tokushima University proposed the ATP-lactate energy risk score (A-LES) for measuring ATP and lactate blood levels to assess acute influenza severity in patients," Akihiko Ishida, applied chemist at Hokkaido University and co-author of the team's latest paper. "However, current methods to measure these levels and other approaches for measuring disease severity can be cumbersome, lengthy or not sensitive enough. We wanted to develop a rapid, sensitive test to help doctors better triage their patients."

That test: A prototype biosensor chip, which uses enzymatic reactions and two sets of electrodes to signal its readings to a connected microcontroller via a potentiostat.

Using the chip is simple: A small blood sample is taken from the patient and mixed with an extraction reagent designed to pull the ATP from the red blood cells. Enzymes and substrates are then added to convert the extracted ATP and lactate in the blood sample to a product detectable by the chip's electrodes: As the current generated in at the electrode rises, it indicates higher levels of ATP and lactate in the sample.

The process takes about five minutes beginning to end, the team claims, and requires very little knowledge or expertise on the part of the person performing the test — which will be reduced still further, the team hopes, with an improved version which will reduce the size of the system for portability while also integrating an ATP extraction method into the chip itself to do away with a processing step.

The paper has been published in the journal Biosensors and Bioelectronics under closed-access terms.