Selective Immobilization of DNA and Antibody Probes on Electrode Arrays: Simultaneous Electrochemical Detection of DNA and Protein on a Single Platform

ArticleinLangmuir 23(16):8285-7 · August 2007with11 Reads
DOI: 10.1021/la701775g · Source: PubMed
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.
    • The individual on/ off switching allows for the fabrication of arrays with multiple biological molecules on multiple electrodes. Various electrochemically triggered immobilization strategies discussed above have been exploited, including electrografting of aryldiazonium salts [25,26], various reactions using surface-confined quinone groups [36,37], quinone-based protecting groups [16,17] , polymer entrap- ment111213 and unspecific adsorption [38]. The read-out of binding events at individual electrodes without relying – as classical bioarrays do – on fluorescence microscopy can be achieved using electrode arrays.
    [Show abstract] [Hide abstract] ABSTRACT: High-density biomolecule arrays are powerful tools for the screening of pharmaceuticals, investigation of biomolecule interactions and patient diagnostics. Surfaces modified with electrochemically-addressable films combined with electrochemical-surface-patterning techniques allow local triggering of DNA and protein immobilization. After a brief overview of classical patterning methods, such as printing, dip-pen nanolithography (DPN) and photolithography, we critically assess electrochemical strategies for local surface modification, such as the use of electrode arrays, electro-DPN and scanning electrochemical microscopy, regarding their potential for fabrication and read-out of bioarrays. Capillary-based scanning probe methods are especially promising tools for truly chemoselective microarray and nanoarray generation due to their high patterning resolution and the possibility for directly probing the surface chemistry.
    Full-text · Article · Jun 2014
    • Here an aniline derivative undergoes a diazotation reaction and the formed aryl diazonium ion can then be electrochemically reduced to an aryl radical. This immobilization method is reported to be more robust against elevated temperatures [11] and less prone to oxidation and reduction [12]. In the recent years the sequence-specific detection of DNA has become also very sensitive.
    [Show abstract] [Hide abstract] ABSTRACT: This paper reviews past and current developments in the field of electrochemical biosensors with a focus on the sequence-specific detection of nucleic acids in real samples. After electrochemical hybridization sensors had been first described in 1993, it took nearly a decade until some of the many proposed protocols were indeed applied to real samples like blood or tissue. Electrochemical transduction schemes used either rely on electroactive moieties such as intercalators, groove binders, covalently attached labels, and products of enzyme markers or they are completely indicator free like impedance-based detection principles. Most detection schemes require a polymerase chain reaction amplification step to allow for sufficient selectivity and sensitivity. Today, several companies develop electrochemical microarrays able to detect dozens to many thousands of sequences in a single experiment. KeywordsElectrochemical biosensor–Hybridization detection–Real sample–Intercalator–Redox label–Indicator free
    Full-text · Article · Dec 2010
  • [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.
    Article · Feb 2008
  • [Show abstract] [Hide abstract] ABSTRACT: A high degree of control over the modification of electrode surfaces is required for many sensing applications. This critical review briefly outlines some of the considerations for interfacial design in amperometric sensors and discusses some of advantages and disadvantages of alkanethiol modified metal electrodes for such applications before concentrating on the modification of electrodes surfaces using aryl diazonium salts. The pros and cons of this chemistry, and the application of aryl diazonium salts for sensing on carbon electrodes is reviewed before recent advances in using this chemistry for modifying metal electrodes are presented.
    Article · Mar 2008
  • [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.
    Article · Mar 2008
  • [Show abstract] [Hide abstract] ABSTRACT: A versatile and simple method is introduced for formation of maleimide-functionalized surfaces using maleimide-activated aryl diazonium salts. We show for the first time electrodeposition of N-(4-diazophenyl)maleimide tetrafluoroborate on gold and carbon electrodes which was characterized via voltammetry, grazing angle FTIR, and ellipsometry. Electrodeposition conditions were used to control film thickness and yielded submonolayer-to-multilayer grafting. The resulting phenylmaleimide surfaces served as effective coupling agents for electrode functionalization with ferrocene and the redox-active protein cytochrome c. The utility of phenylmaleimide diazonium toward formation of a diazonium-activated conjugate, followed by direct electrodeposition of the diazonium-modified DNA onto the electrode surface, was also demonstrated. Effective electron transfer was obtained between immobilized molecules and the electrodes. This novel application of N-phenylmaleimide diazonium may facilitate the development of bioelectronic devices including biofuel cells, biosensors, and DNA and protein microarrays.
    Article · Apr 2008
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