Electrochemical electrodes work through a combination of electric current and a chemical substance or enzyme which reacts when certain substances are present. The most common and well-known application for these sensors are glucose strips, where the sugar content of blood is measured.
Glucose, or blood sugar, is not the only thing that can be detected and measured with the help of these sensors. They can be tailored to detect almost anything, from pH levels of liquids, to certain hormones in saliva or urea.
An example would be a sensor that Screentec developed in cooperation with Oulu’s university of applied sciences (seen on the left) that can detect stress hormones from saliva samples. These were used for research into stress reactions of people.
Most electrochemical sensors and electrodes are single use only. Meaning that they are cannot be used again and are thrown away after use. Because of this, they are often made from paper and use graphite instead of silver, to make them more environmentally friendly. The problem is that many of the measurements of the human body are more valuable if you have trends, rather than a single snapshot in time.
Development is ongoing to make electrochemical sensors and electrodes which can measure constantly which allows user to follow trends and get a more complete picture of a subject’s health.