1. A method of using a biosensor for identifying toxins with at least one processor, comprising the steps of: a) obtaining at least one time-dependent control signal generated by the biosensor, the biosensor comprising a cell including naturally-occurring, free-living, indigenous photosynthetic organisms, wherein the at least one time-dependent control signal comprises a fluorescence induction signal emitted by the photosynthetic organisms in water without the presence of one or more toxins selected from chemical, biological or radiological agents; b) obtaining a time-dependent biosensor signal that comprises a fluorescence induction signal emitted by the photosynthetic organisms in water and in a presence of the one or more toxins selected from chemical, biological or radiological agents; c) processing, with said at least one processor, said time-dependent biosensor signal to extract statistical features from multi-level wavelet coefficients obtained from wavelet coefficient analysis of said time-dependent biosensor signal; d) determining, with said at least one processor, at least one parameter relating to toxicity of said water from said extracted statistical features of wavelet coefficients by comparing with said at least one time-dependent control signal; e) identifying, with said at least one processor, which of said chemical, biological or radiological agents are present in said water from said determined at least one parameter; and f) eliminating, through said identifying, false-positives resulting from the photo-inhibition effect.