MCQ Detailed View

A biosensor is an analytical device used to detect and measure a biological substance, typically by converting its presence or concentration into an electrical signal. It combines a biological sensing element (such as enzymes, antibodies, nucleic acids, or microorganisms) with a transducer that converts biological reactions into measurable data.

The most common and widely used application of a biosensor is to measure blood glucose levels, particularly for people with diabetes. In this case, the biosensor uses an enzyme (like glucose oxidase) that reacts specifically with glucose present in the blood. This reaction generates an electrical signal proportional to the glucose concentration, which is then displayed on a meter.

Biosensors work on three main components:

1. 
   

   Biological element (bioreceptor) – detects the target substance.

   
   


2. 
   

   Transducer – converts biological activity into an electrical signal.

   
   


3. 
   

   Detector or display system – shows the results in readable form.

   
   

While biosensors can measure many biological and chemical substances, their primary and most popular use is blood glucose monitoring, making them a vital tool in healthcare. Other potential uses include measuring toxins, pathogens, pH levels, or specific proteins in medical diagnostics, environmental monitoring, and food quality control.

Biosensors are important in modern biology because they provide rapid, accurate, and real-time results, often with only a small sample of blood or fluid. This technology has revolutionized patient care, allowing individuals to monitor their health at home with portable biosensor devices like glucose meters.

Thus, the correct answer is Blood glucose level, as it represents the primary and most well-known application of biosensors in biological science and medical diagnostics.