Abstract: The present invention relates to methods and compositions for identifying a pathogen. The inventions provide an antibody-based biosensor probe comprising (AUNT) in combination with a polymer-coated magnetic nanoparticle. In particular, a nanoparticle-based biosensor was developed for detection of Escherichia coli O157:H7 bacterium in food products. Further described are biosensors for detecting pathogens at low concentrations in samples. Even further, a gold nanoparticle-based electrochemical biosensor detection and amplification method for identifying the insertion element gene of Salmonella enterica Serovar Enteritidis is described. The present invention provides compositions and methods for providing a handheld potentiostat system for detecting pathogens outside of the laboratory. The AUNT biosensor system has applications detecting pathogens in food, water, beverages, clinical samples, and environmental samples.

Abstract: A multi-array membrane strip biosensor device (10, 20) using a fluid mobile conductive polymer as reporter is described. The biosensor device (20) is designed to detect multiple analytes at low concentrations in near real-time with an electronic data collection system. The biosensor device can be small. The device can be used to detect pathogens, proteins, and other biological materials of interest in food, water, and environmental samples. The device can also be used for on-site diagnosis and against potential bioterrorism. Potential users include food processing plants, meat packaging facilities, fruit and vegetable packers, restaurants, food and water safety inspectors, food wholesalers and retailers, farms, homes, medical profession, import border crossing personnel, and the police force, military, space habitation and national security.

Abstract: A conductive polymer of polyaniline (PANi), tetracyanoquinodimethane (TCNQ) and a transferrin family member. The conductive polymer can be used in conductometric assays, including biosensor devices. One particular transferrin family member provided in the polymer is lactoferrin.

Abstract: A DNA-polypyrrole based biosensor and methods of using the biosensor for the rapid detection of Escherichia Coli and other microorganisms. The DNA-polypyrrole biosensor can be used to detect dangerous micoorganisms for monitoring water quality of a sample from a drinking water or food source. The biosensor can use genomic DNA extracted from natural environments in field settings for the rapid detection of microorganisms to provide an early warning of water contamination.

Abstract: A method and device for the rapid detection of microorganisms by detection of a change of impedance as a result of the microorganism being bound between interdigitated electrodes is described. In particular, the present invention relates to a handheld device to be used for the detection and, in many instances, the identification of the microorganism.