Biosensor enables glucose monitoring without needle pricks

Checking the blood glucose levels is an everyday part in life of many diabetics. There are various less invasive solutions under development which could be used to avoid this unpleasant task, and researchers from Fraunhofer Institute recently presented their solution in a form of a biosensor developed in cooperation with researchers from a Dutch medical technology firm NovioSense BV.

Unlike previously available bioelectric sensors which were too big, too imprecise and consumed too much power, the new biosensor developed by researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems (Fraunhofer IMS) in Duisburg is much smaller and more durable.

The principle of measurement involves an electrochemical reaction that is activated with the aid of an enzyme. Glucose oxidase converts glucose into hydrogen peroxide (H2O2) and other chemicals whose concentration can be measured with a potentiostat. This measurement is used for calculating the glucose level. Aside a nanopotentiostat, the chip developed by Fraunhofer researchers has a whole diagnostic system and its dimensions are just 0.5 x 2 millimetres.

“It even has an integrated analog digital converter that converts the electrochemical signals into digital data”, said explains Tom Zimmermann, business unit manager at Fraunhofer IMS. “In the past, you used to need a circuit board the size of a half-sheet of paper, and you also had to have a driver. But even these things are no longer necessary with our new sensor.”

The glucose sensor is engineered by the researchers at NovioSense BV, and it can be mass produced in a cost-effective way. It is a non-invasive, wireless sensor able to send and receive data packages to devices such as smart phones. Another benefit of its wireless property is the fact it can be supplied with power through radio frequency.

The system also consumes less power than previously used systems (less than 100 microamperes instead about 500 microamperes at five volts), thus enabling the patient to wear the sensor for weeks, or even months.

Aside getting rid of needles in glucose monitoring, the researchers from Fraunhofer IMS envision that their system could be used to control an implanted miniature pump that can inject proper amounts of insulin according to the measured glucose levels.