1. A method of biosensor-based detection of toxins, comprising the steps of: providing at least one time-dependent control signal generated by a biosensor in a gas or liquid medium; obtaining a time-dependent biosensor signal from said biosensor in said gas or liquid medium to be monitored or analyzed for the presence of one or more toxins selected from chemical, biological or radiological agents; processing said time-dependent biosensor signal to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis, and determining at least one parameter relating to toxicity of said gas or liquid medium from said feature vectors based on reference to said control signal.