Team members and illustrator Inês Montalvão continue to work on the creation of an art-based book on biosensors, and on Bioassembler’s contributions to this field.

Here is the first entry in this dictionary:

Introducing a biosensor

A tool to detect different substances using a biological component. In simple terms, this is a biosensor: a “biological sensor”.

We don’t need to go far to understand what a sensor does. Our nose and tongue are equipped with sensors. When we eat a lemon, we feel the sour taste on our tongue and we can detect the characteristic lemon smell generated by compounds such as limonene, linalool and citral.

Just as we humans can detect odours and flavours, sensors respond to stimuli, such as heat, light, or pressure, and generate signals that can be measured or interpreted.

Biosensors work in the same logic. These devices can detect a wide range of substances, such as proteins, pathogens, and toxins, from samples such as blood, saliva, or water.

A biosensor is made of two main components: a biological element, known as a bioreceptor, such as an enzyme or antibody, and a transducer, an electronic device that changes one form of energy into another.

An interesting type of transducer is a microphone. It transforms sound waves into electrical signals. When it comes to biosensors, this transformation can happen in various ways, like a shift in the brightness of the biological element.

How do biosensor components work together? The bioreceptor recognizes and interacts with the substance to be detected, called a target analyte, and generates a signal that the transducer converts into a measurable output.

Let’s think of a classic case: a biosensor applied to monitor glucose.

In this context, a blood sample is used, and glucose (the target analyte) is detected through its interaction with a specific enzyme that acts as a bioreceptor.

While most glucose-monitoring biosensors are electrochemical, there are also other types of biosensors, such as optical and piezoelectric ones.

Each type of biosensor has advantages and limitations and can depend on the target analyte, the application, and the environment. But let’s save that topic for later.