Targeted Deposition of Antibodies on a Multiplex CMOS Microarray and Optimization of a Sensitive Immunoassay Using Electrochemical Detection
Open Access
- 19 March 2010
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 5 (3), e9781
- https://doi.org/10.1371/journal.pone.0009781
Abstract
The CombiMatrix ElectraSense® microarray is a highly multiplex, complementary metal oxide semiconductor with 12,544 electrodes that are individually addressable. This platform is commercially available as a custom DNA microarray; and, in this configuration, it has also been used to tether antibodies (Abs) specifically on electrodes using complementary DNA sequences conjugated to the Abs. An empirical method is described for developing and optimizing immunoassays on the CombiMatrix ElectraSense® microarray based upon targeted deposition of polypyrrole (Ppy) and capture Ab. This process was automated using instrumentation that can selectively apply a potential or current to individual electrodes and also measure current generated at the electrodes by an enzyme-enhanced electrochemical (ECD) reaction. By designating groups of electrodes on the array for different Ppy deposition conditions, we determined that the sensitivity and specificity of a sandwich immunoassay for staphylococcal enterotoxin B (SEB) is influenced by the application of different voltages or currents and the application time. The sandwich immunoassay used a capture Ab adsorbed to the Ppy and a reporter Ab labeled for fluorescence detection or ECD, and results from these methods of detection were different. Using Ppy deposition conditions for optimum results, the lower limit of detection for SEB using the ECD assay was between 0.003 and 0.01 pg/ml, which represents an order of magnitude improvement over a conventional enzyme-linked immunosorbant assay. In the absence of understanding the variables and complexities that affect assay performance, this highly multiplexed electrode array provided a rapid, high throughput, and empirical approach for developing a sensitive immunoassay.This publication has 19 references indexed in Scilit:
- CombiMatrix oligonucleotide arrays: Genotyping and gene expression assays employing electrochemical detectionBiosensors and Bioelectronics, 2007
- Electrochemically Generated Acid and Its Containment to 100 Micron Reaction Areas for the Production of DNA MicroarraysPLOS ONE, 2006
- Electrochemical Detection of Short DNA Oligomer Hybridization Using the CombiMatrix ElectraSense Microarray ReaderElectroanalysis, 2006
- Electrochemical sensors based on conducting polymer—polypyrroleElectrochimica Acta, 2006
- Recent Advances in Electrochemical Enzyme ImmunoassaysElectroanalysis, 2005
- Immunoassays based on electrochemical detection using microelectrode arraysBiosensors and Bioelectronics, 2004
- Electrochemical SensorsAnalytical Chemistry, 2004
- Application of Conducting Polymers in Chemical AnalysisMicrochimica Acta, 2003
- Chemical Biological Sensors Based on Advances in Conducting Electroactive PolymersMicrochimica Acta, 2003
- Antigen detection using microelectrode array microchipsAnalytica Chimica Acta, 2001