What do biosensors primarily rely on?

Biosensors primarily rely on biological materials for detection purposes. This includes the use of enzymes, antibodies, microorganisms, or nucleic acids, which specifically interact with the target analyte. This interaction is the basis for the sensor's ability to detect and quantify substances, including pathogens, toxins, or other biomolecules within a sample.

The biological component is combined with a transducer that converts the biological response into a measurable signal, enabling the identification and analysis of the target substance. By utilizing biological materials, biosensors can achieve high specificity and sensitivity for detecting particular analytes, making them valuable tools in various fields, including medical diagnostics, environmental monitoring, and food safety.

The other options do not encapsulate the primary function of biosensors effectively. For example, while chemical reactions and physical changes can play a part in how biosensors operate, they do not define the core reliance on biological materials that is fundamental to biosensor technology. User inputs, while essential for interpreting results, are more about data processing rather than the detection mechanism itself.