Abstract: Methods of detecting bioactive compounds include exposing compounds to one or more classes of chromatophores and measuring or sensing associated changes in one or more of the chromatophores. Representative methods permit identification and quantification of neurotransmitters, toxins, hormones, and chemical warfare agents with or without prior knowledge of the content of a sample. In some examples, chromatophores based on Betta fish are used. Cytosensor apparatus using such chromatophores include means for exposing chromatophores to a sample and optical detection systems for assessing changes in chromatophore optical properties. Compounds can be identified or quantified based on a red-green-blue or hue saturation-value representations of transmitted or reflected light or based on other characterizations of transmitted or reflected light.

Abstract: Living cells can be used to identify or quantify bioactive conditions, including without limitation, chemicals, biological pathogens, and environmental conditions, such as pH, in samples based on changes in, for example, cell color, morphology and/or physiology. Such changes can be directly detected or detected with the aid of instrumentation. One embodiment of the method comprises exposing a system to a bioactive condition, such as a chemical agent, a biological pathogen, an environmental condition, such as pH, etc., and combinations of such conditions. The system then exhibits a response to the bioactive condition. The response of the system, or a portion thereof, to the bioactive condition is then represented, such as by digital images. The method then involves attempting to classify a scenario by database comparison. Classification can be in terms of numeric or non-numerical classifiers. Typically, the system comprises living cells.