Sensors2

Question 1

Function Based Sensing

Answer 1

Relies on the biological activity or function of the sensor element

The sensing mechanism is usually tied to a specific biological reaction that the sensor element can catalyse or undergo in the presence of the target analyte

e.g. Enzyme based sensor, the enzyme (sensor element) catalysed a reaction involving the analyte, and this reaction produces a detectable signal.

Question 2

Structured/Affinity Sensing

Answer 2

Relies on the physical binding or interaction between the sensor and the target analyte. Binding is often highly specific, and it occurs without a chemical reaction or transformation. The sensor detects the presence of of the analyte based on changes in mass, refractive index, or electrical impedance that occur when the analyte binds to the sensor material.

e.g. Antibody-based sensor where the antibody (sensor element) binds to a specific antigen (the analyte) binds to a specific antigen (the analyte). This binding event can be detected through various means, such as changes in fluorescence or electrical conductivity.

Question 3

Function sensors pros

Answer 3

High Specificity

High Sensitivity

Versatility - Wide range of biological activities that can be used in function-based sensing. From enzymatic reactions to cell metabolic responses and nucleic acid hybridization. Applicable to a broad range of analytes and applications.

Question 4

Function Sensors Cons

Answer 4

Stability - Susceptible to environmental conditions such as temperature and pH, and they can lose their activity over time. Limits shelf life and field usability of sensor

Inteference - The biological activity used in function based sensing can be affected by other substances present in the sample, leading to false positives or negatives.