Noninvasive Glucose Detection in Saliva with Organic Transistors
. Sensitive, Selective, Flexible and Low-cost Biosensor .
Diabetic patients need to monitor blood glucose level regularly and frequently, however conventional methods of taking blood sample for measuring glucose level are painful. To tackle this problem, we successfully developed an ultra-sensitive dual gate organic electrochemical transistor (OECT)-based biosensor which could detect glucose in saliva by no invasive approaches. The newly invented biosensor is highly sensitive to glucose and capable of measuring the range of glucose in saliva accurately in a convenient, safe and inexpensive manner.
The biosensor is modified with glucose oxidase (GOx) which offers a quick detection of saliva with high stability, selectivity and sensitivity. By detecting the electrical current, the glucose level can be calculated accordingly. To block other active biological elements in saliva (e.g,.dopamine, uric acid and ascorbic acid, etc,.), a thin layer of Polyaniline (PANI) / Nafion / CHIT film was coated on dual gate electrode. The highly sensitive biosensor shows a low detection limit of 1 nM, which is nearly 10 4 times sensitive than the conventional electrochemical approaches for measuring blood glucose. More importantly, the glucose biosensor fabricated on flexible substrates can perform in a variety of curved and moving surfaces, including human skin, smart textile and medical bandage. Thus, it has great potential for development into wearable electronic applications, such as wearable biosensor for the analysis of glucose level in sweat during exercise.