Environmental biotechnology is the integration of natural sciences and engineering in order to achieve the application of organisms, cells, parts thereof and molecular analogues for the protection and restoration of the quality of our environment. Biotechnological processes to protect the environment have been used for almost a century now, even longer than the term "biotechnology" exists. Biotechnological techniques to treat waste before or after it has been brought into the environment are components of environmental biotechnological tools. Biotechnology can also be applied industrially for use in developing products and processes that generate less waste and use less nonrenewable resources and consume less energy. A biosensor is an analytical device that integrates a biological sensing element (e.g., an enzyme or an antibody) with a physical (e.g., optical, mass, or electrochemical) transducer, whereby the interaction between the target and the bio-recognition molecules is translated into a measurable electrical signal. Potent alternatives to conventional analytical techniques are Optical biosensors that exploit light absorption, fluorescence, luminescence, reflectance, Raman scattering and refractive index. Devoid of any time-consuming sample concentration and or prior sample pretreatment steps these biosensors provide rapid, highly sensitive, real-time, and highfrequency monitoring. Although optical biosensors have great potential applications in the areas of environmental monitoring, food safety, drug development, biomedical research, and diagnosis. Their use in fields of environmental pollution control and early warning is still in the early stages. Biosensors are classified according to their transduction principle such as optical, electrochemical and piezoelectric or based on their recognition element as immunosensors, apt sensors, genosensors, and enzymatic biosensors, when antibodies, aptamers, nucleic acids, and enzymes are, respectively, used.
