Biosensor

Workings of a biosensor

A biosensor consists of a specific biological recognition element and an element that transforms the change of the recognition into a measurable electrical signal (the transducer, see Figure 1).

The recognition element can be a protein, an antibody, a DNA-string or an enzyme. These natural molecules specifically react or bind to one particular other substance.

For example, an antibody adheres to a virus or a DNA-string adheres to the complementary strand to form a helix. This process changes the biosensor permanently, most biosensors can therefore only be used once.

The transducer converts the change into a measurable electrical signal. An electrochemical biosensor usually uses the working electrode as a transducer.

Point-of-care applications

Biosensors are typically used in point-of-care applications. These are situations where a certain test has to be performed on-site and there is no possibility to have the test performed in a laboratory.

An example of this is an ambulance worker who, in the event of an accident, has to determine whether the injured person is infected with HIV or not. This test can be performed with a portable potentiostat, such as the Sensit Smart or EmStat combined with the right biosensor.

The blood sugar test is also an example. Patients suffering from diabetes can carry out this test at home without having to go to the hospital laboratory.

Multiple-use biosensors

Some biosensors contain substances that can capture multiple substances in one experiment. These biosensors can be used by potentiostats with an integrated multiplexer, such as the EmStat MUX. This potentiostat can measure several different electrochemical reactions simultaneously.