A new class of biosensors and methods for making and using same are disclosed. The biosensors are multi-layered membrane composites, where at least one layer is prepared by the layer-by-layer process and at least one layer is responsive to changes is a property of a biological system such as changes in the concentration of an atom, ion, molecule or molecular assembly. Because the biosensors are multi-layered, a single biosensor is capable monitor a number of different properties of a biological system simultaneously. The biosensors are monitored by systems that impinge an excitation waveform on the biosensors and analyze a reflected and/or a transmitted resultant waveform. Additionally, the biosensors can be associated with field activated electronic components so that implantable, self-contained analytical devices can be constructed and monitored by field generators, where data is transmitted to an analyzer after field activation.