Biosensor Arrays for Environmental Monitoring

Environmental monitoring involves several steps such as sampling, sample handling and sample transportation to specialized laboratories, sample preparation and analysis. Traditional environmental monitoring approaches are based on discrete sampling methods followed by laboratory analysis. These approaches do not improve our understanding of the natural processes governing chemical species behavior, their transport and bioavailability, or the relationship between anthropogenic releases and their long-term impact on aquatic systems[1]. The challenge of environmental monitoring in situ requires new and improved analytical devices featuring precision, sensitivity, specificity, rapidity, and ease of operation to detect decreasing concentrations of an ever growing array of pollutants. Such devices must be comparable to or better than traditional analytical systems, and must be simple to handle, small, cheap, able to provide reliable information in real-time, and must be sensitive and selective for the analyte of interest, and suitable for in situ monitoring[2]. Biosensors not only fulfill all these requirements but also have applications in many areas such as clinical diagnostics, forensic chemistry, pharmaceutical studies, food quality control and environmental monitoring. A biosensor is an analytical device for the detection of an analyte that combines a biological component with a physicochemical detector component. It consists of 3 parts: (1) the sensitive biological element (biological material such as tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc.), a biologically derived material or biomimic; (2) the transducer or the detector element (works in a physicochemical way; optical, piezoelectric, electrochemical, etc.) that transforms the signal resulting from the interaction of the analyte with the biological element into another signal that can be more easily measured and quantified; (3) associated electronics or signal processors that are primarily responsible for the display of the results in a user-friendly way[3]. Depending on the type of transduction mechanism applied and the bio-recognition element employed, the potential for these devices for detection can be enormous. The technological development and the success in single analyte detection propelled advances in the miniaturization of sensors along with multi-analyte detection with sensitivities ranging in the nano-mole to