This volume describes the most recent advances in the design, research, development, and application of environmental chemical sensors and biosensors. Topics encompass the rational assembly of dynamic macromolecules, biocomponent stability, DNA based biosensors, molecular beacons, electronic nose, multianalyte-transducers, sensor systems and others as tools for environmental monitoring. It provides perspective on how recent works in chemical and biological sensors are meeting the challenges of environmental monitoring through enhanced specificity, fast response times, and the ability to determine multiple analytes with little or no need for sample preparation steps in complex samples.