Abstract: The present invention provides an improvement method and a system for decreasing the limit of detection of the presence of an analyte in a sample. In particular, the present invention provides an article or a system, such as a diagnostic kit, for detecting the presence of an analyte in a sample, comprising (i) a microsphere coated with an affinity ligand, or a spore or bacterium expressing one or more proteins on the surface thereof, (ii) a signal-producing substances, and (iii) a binding agent, wherein the signal-producing substance is conjugated with the binding agent and an antibody specific to the affinity ligand on the microsphere or the protein expressed by the spore or bacterium, wherein the signal-producing substances are conjugated to the microsphere, spore or bacterium through the binding of the antibodies specific to the affinity ligand or the protein.

Abstract: The present invention provides a method and a system for detecting the presence of an analyte in a sample. In particular, the present invention provides a system, such as a diagnostic kit, for detecting the presence of an analyte in a sample, comprising (a) a recombinant bacterium or spore expressing one or more recombinant proteins on the surface thereof, wherein the recombinant protein specifically binds to the analyte directly or through a binding agent that specifically binds to the recombinant protein and the analyte, and (b) a signal-producing substance that can be detected.

Abstract: The present invention provides a method and a system for detecting the presence of an analyte in a sample. In particular, the present invention provides a system, such as a diagnostic kit, for detecting the presence of an analyte in a sample, comprising (a) a recombinant bacterium or spore expressing one or more recombinant proteins on the surface thereof, wherein the recombinant protein specifically binds to the analyte directly or through a binding agent that specifically binds to the recombinant protein and the analyte, and (b) a signal-producing substance that can be detected.

Abstract: The present invention provides a method and a system for detecting the presence of an analyte in a sample. In particular, the present invention provides a system, such as a diagnostic kit, for detecting the presence of an analyte in a sample, comprising (a) a recombinant bacterium or spore expressing one or more recombinant proteins on the surface thereof, wherein the recombinant protein specifically binds to the analyte directly or through a binding agent that specifically binds to the recombinant protein and the analyte, and (b) a signal-producing substance that can be detected.

Abstract: This invention disclosed a method to detect bioparticles in the biological samples (stools, urine, or other body fluids). Bioparticles (e.g. virus, bacteria, and cells) often serve as carrier/indicator of pathogens and/or toxins. The method employs a substrate with interlaced comb-like electrodes on which a certain amount of sample mixed with antibodies-coated gold nanoparticles is dropped. Then the alternative signals with specific frequency bands are applied on the comb-like electrodes so that under such a DEP force the Au-modified bioparticles can be separated from the other constituents of the sample and can be absorbed effectively onto the edges of the electrodes. After rinsed with water to remove the residual sample several times, the device will be measured for the impedance of the absorbed bioparticles on the edges of the electrodes. The measured impedance deviation in comparison with that of the reference empty comb-like electrodes will quantify the amount of the absorbed bioparticles.