Cell-based Biosensors

Cell-based biosensors are biosensors that use living cells as the biorecognition factor to identify a target analyte and determine whether it is present or active. These biosensors are based on cells' capacity to react to alterations in their surroundings by altering their metabolic activity or by expressing particular genes or proteins.

Cell-based biosensors can be classified into two main categories: whole-cell biosensors and cell-free biosensors. Cell-free biosensors use cell extracts or purified proteins, whereas whole-cell biosensors use complete living cells as the biorecognition component.

Whole-cell biosensors are further categorized based on the type of biological response detected, such as pH changes, oxygen consumption, or cell electrical characteristics. Whole-cell biosensors include the following:

Microbial biosensors: These biosensors use bacteria or yeast cells that have been genetically engineered to produce a detectable signal in response to specific analytes, such as light or fluorescence.

Enzyme-based biosensors: These biosensors are made up of cells that manufacture or express enzymes that catalyze a reaction with the target analyte, producing a detectable signal.

Ion channel-based biosensors: Ion channel-based biosensors use cells that produce ion channels that respond to changes in the concentration of certain ions, such as potassium or calcium ions.

However, cell-free biosensors make use of purified proteins or cell extracts that can bind to or initiate a reaction with the target analyte. Cell-free biosensors include, for example:

Immunosensors: These biosensors bind selectively to the target analyte using pure antibodies or antibody fragments, producing a detectable signal.

Enzyme-linked biosensors: These biosensors use purified enzymes that catalyze a reaction with the target analyte, resulting in a measurable signal.

Applications for cell-based biosensors include environmental monitoring, drug development, and clinical diagnostics. However, maintaining cell viability and function over time, as well as the requirement for specific tools and knowledge, are the key difficulties connected with the use of cell-based biosensors.