GNCIA allows a sensitive and selective detection of HIV-1 infections with a sensitivity of 5 pg/ml.

For the first time, we have engineered streptavidin labeled fluorescent silver nanoparticles for their application in immunosensing of biomolecules which will significantly increase sensitivity without compromising the specificity. Plasma samples that were HIV Àve showed no interference with detection of HIV-1 p24 antigen. This technology can be used in resource limited settings and easily adopted for the detection of other pathogen antigens.

and sensitive paper-based HIV-1 p24 antigen assay may be useful in preventing HIV transmission by blood transfusion in resource-limited settings by reducing the antibody negative, infectious window period in blood donors and for early diagnosis of HIV infected individuals where nucleic acid-based testing is not practical or feasible.

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We have engineered streptavidin labelled Europium doped fluorescent silica nanoparticles which significantly increased sensitivity without compromising the specificity of the immunoassay. As a proof of concept, a time resolved fluorescence based sandwich immunoassay was developed to detect HIV-1 p24 antigen in clinical specimens. The detection range of the silica nanoparticle based immunoassay (SNIA) was found to be between 0.02 to 500 pg/mL in a linear dose dependent manner. SNIA offers 1000 fold enhancement over conventional colorimetric ELISA. Testing of plasma samples that were HIV negative showed no false positive results in the detection of HIV-1 p24 antigen. This highly sensitive p24 assay can help improve blood safety by reducing the antibody negative window period in blood donors in resource limited settings where nucleic acid testing is not practical or feasible. This technology can also be easily transferred to a lab-on-a-chip platform for use in resource limited settings and can also be easily adopted for the detection of other antigens.

Rapid detection and identification of pathogenic microorganisms is fundamental to minimizing the spread of infectious disease, and informing clinicians on patient treatment strategies. This need has led to the development of enhanced biosensors that utilize state of the art nanomaterials and nanotechnology, and represent the next generation of diagnostics. A primer on nanoscale biorecognition elements such as, nucleic acids, antibodies, and their synthetic analogs (molecular imprinted polymers), will be presented first. Next the application of various nanotechnologies for biosensor transduction will be discussed, along with the inherent nanoscale phenomenon that leads to their improved performance and capabilities in biosensor systems. A future outlook on characterization and quality assurance, nanotoxicity, and nanomaterial integration into lab-on-a-chip systems will provide the closing thoughts. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > Biosensing.

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