Reagentless electrochemical immunoassay using electrocatalytic nanoparticle-modified antibodies

Sandia National Laboratories, PO Box 5800, MS-0892, Albuquerque, NM 87185, USA.
Chemical Communications (Impact Factor: 6.83). 08/2007; DOI: 10.1039/b704012a
Source: PubMed


We describe a new approach for reagentless electrochemical immunoassay sensing in which Au/Pd NPs can be "loaded" onto antibodies to create an electrocatalytic antibody that is sensitive to the oxygen reduction reaction.

4 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: A proof of concept procedure for the electroaddressable covalent immobilization of DNA and protein on arrayed electrodes along with simultaneous detection of multiple bioagents in the same sample solution is described. Carboxyphenyldiazonium was selectively deposited onto five of nine individually addressable electrodes in an array via bias assisted assembly. Amine functionalized DNA probes were covalently coupled to the carboxyl surface via carbodiimide chemistry. This was followed by the covalent immobilization of diazonium-antibody conjugates into the remaining four electrodes via cyclic voltammetry. Simultaneous electrochemical detection of a DNA sequence related to the breast cancer BRCA1 gene and the human cytokine protein interleukin-12, which is a substantial component in the immune system response and attack of tumor cells, is reported. These results demonstrate the possibility of selective patterning of diverse biomolecules on a single device and may have significant implications for future development of microarrays and biosensors.
    Langmuir 08/2007; 23(16):8285-7. DOI:10.1021/la701775g · 4.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this article we review recent work in our laboratory towards the realization of a multianalyte microelectrode detection platform capable of discriminating chemicals and different biomolecules simultaneously. The functionalization of electrodes with aryl diazonium salts provides an electrically addressable deposition procedure capable of immobilizing a wide range of molecules. We demonstrate control over surface density and electron transfer kinetics as well as the activation of individual electrodes in an array. The direct electrically-addressable immobilization of diazonium-modified proteins is shown to be suitable for the construction of multianalyte immunosensors and the immobilization of horseradish peroxidase leading to the direct electron transfer between the redox enzyme and the electrode. The use of catalytic nanoparticles leads to the construction of a reagent-less immunosensor and the simultaneous detection of DNA and proteins on the same electrode array is demonstrated.
    Electroanalysis 02/2008; 20(6):671 - 679. DOI:10.1002/elan.200704129 · 2.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: (Chemical Equation Presented) Holding cells: Individual gold electrodes can be activated by phenylboronic acid diazonium salts for the facile and reversible immobilization of eukaryotic cells (see scheme). This platform provides a simple method for on-demand release of captured cells (yeast and macrophage) and can be used in single-cell or array-based studies.
    Angewandte Chemie International Edition 03/2008; 47(14):2631-4. DOI:10.1002/anie.200704597 · 11.26 Impact Factor
Show more