What are Biosensors?

NewsGuard 100/100 Score

The term “biosensor” is short for “biological sensor.” The device is made up of a transducer and a biological element that may be an enzyme, an antibody or a nucleic acid. The bioelement interacts with the analyte being tested and the biological response is converted into an electrical signal by the transducer. Depending on their particular application, biosensors are also known as immunosensors, optrodes, resonant mirrors, chemical canaries, biochips, glucometers and biocomputers.  A commonly cited definition of a biosensor is:

“A chemical sensing device in which a biologically derived recognition is coupled to a transducer, to allow the quantitative development of some complex biochemical parameter.”

Parts of a biosensor

Every biosensor comprises:

  • A biological component that acts as the sensor
  • An electronic component that detects and transmits the signal

Biosensor elements

A variety of substances may be used as the bioelement in a biosensor. Examples of these include:

  • Nucleic acids
  • Proteins including enzymes and antibodies. Antibody-based biosensors are also called immunosensors.
  • Plant proteins or lectins
  • Complex materials like tissue slices, microorganisms and organelles

The signal generated when the sensor interacts with the analyte may be electrical, optical or thermal. It is then converted by means of a suitable transducer into a measurable electrical parameter – usually a current or voltage.


Biosensor probes are becoming increasingly sophisticated, mainly owing to a combination of advances in two technological fields: microelectronics and biotechnology. Biosensors are highly valuable devices for measuring a wide spectrum of analytes including organic compounds, gases, ions and bacteria.

History of biosensors

The first experiment to mark the origin of biosensors was carried out by Leland C. Clark. For his experiment, Clark used platinum (Pt) electrodes to detect oxygen. He placed the enzyme glucose oxidase (GOD) very close to the surface of platinum by trapping it against the electrodes with a piece of dialysis membrane. The enzyme activity was modified according to the surrounding oxygen concentration. Glucose reacts with glucose oxidase (GOD) to give gluconic acid and produces two electrons and two protons, thereby reducing GOD. The reduced GOD, the electrons, protons and the surrounding oxygen all react to give hydrogen peroxide and oxidized GOD (the original form), therefore making more GOD available for more glucose to react with. The higher the glucose content, the more oxygen is consumed and the lower the glucose content, the more hydrogen peroxide is produced. This means either an increase in hydrogen peroxide or a decrease in oxygen can be measured to give an indication of the glucose concentration.

Further Reading

Last Updated: Jun 16, 2023


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.