A significant disadvantage of many biosensors is the requirement of labels or reagents for sensitive and specific biological detection. We have shown that utilization of electrocatalytic nanoparticles allows for reagent-less and highly sensitive protein detection. This project continues to focus on the development of reagent-less and label-free methods for biological detection using the unique properties of nanoparticles. TEM images to the right show growth of Pd nanoparticles on antibodies.
The majority of biosensors in use and reported in the literature require labels or reagents for bioagent detection. Although these devices are specific and sensitive, the use of environmentally sensitive labels and large volumes of reagents is a significant hurdle in producing robust field deployable and autonomous biological sensors. Electrocatalytic nanoparticles have drawn much interest for biological detection as they effectively serve as inorganic enzymes, generating a signal analogous to that obtained from enzymatic turnover with significant advantages over enzymes including increased thermal and environmental stability. We have developed a reagent-less immunoassay using nanoparticle modified antibodies and are developing a reagent-less and label-free biosensors using electrocatalytic nanoparticles.
We have developed new approach for electrochemical immunoassay sensing in which Pd NPs can be loaded onto an anti-TNF-α antibody to create an electrocatalytic antibody . Gold particles are first covalently linked to the antibody (step A below). These gold nanoparticles then act as a seed for growth of a palladium shell (step B below).
“Reagent-less Electrochemical Immunoassay Using Electrocatalytic Nanoparticle-Modified Antibodies”
R. Polsky, J. C. Harper, D. R. Wheeler, S. M. Dirk, J. A. Rawlings, S. M. Brozik, ChemComm, 2007, 2741 - 2743.
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