Biosensors for monitoring pollutants in the environment

Preserving and improving environmental quality are major concerns for our society. The means used to monitor and measure environmental quality in its various compartments (air, water, soil) are essentially based on physico-chemical approaches.

The latter are particularly sensitive and specific for accurately identifying and assessing the concentrations present in the samples analyzed. However, they are constrained by their scope, which is limited to the range of compounds that can be measured. What's more, these approaches generally require complex and costly equipment, as well as highly qualified personnel. This last point is an obstacle to their deployment in the environment, given the complexity and diversity of matrices (soil/air/water), and generally restricts measurement campaigns to limited geographical areas and/or with a coarse mesh of the study space.

In this context, biosensors appear as technological alternatives likely to meet these limitations by providing information not available via physico-chemical approaches (toxicity, bioavailability, biodegradability). For several decades now, researchers have been using these approaches for environmental monitoring applications. Several avenues have been explored, based on different architectures both for the biological mechanisms involved in the detection process (DNA, proteins, cells) and for the signals collected.

This article will first review the definition and operating principle of a biosensor, before going on to present the main families of biosensors in detail. The first two sections will focus on the principle and architecture of biosensors, with illustrations and diagrams. The third section of the article will focus on the applicability of these metrological strategies in the context of environmental measurement.