Electrical readout of protein microarrays on regular glass slides

Diana Bonilla, Maria Mallen, Roberto De La Rica, Cesar Fernandez-Sanchez, Antoni Baldi

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

A new approach for the electrical readout of microarrays prepared on regular glass slides, using an array of impedimetric transducers (interdigitated electrodes, IDEs) is presented in this work. Impedance detection relies on the use of a urease-labeled immunoassay scheme. Urease is able to produce an increase in conductivity by hydrolysis of the urea substrate, which is measured with the IDEs and directly related to the amount of target analyte. Unlike previous electrical microarrays, the assay does not take place on top of the transducers but on a regular glass slide, which may enable the development of compact multiplexed analytical systems with lower cost per assay. A droplet of solution with the enzymatic substrate is deposited on each transducer of the array, and the microarray is positioned at a short distance (300 μm) so that each droplet wets one transducer and one spot of the microarray. This procedure allows reusing the transducer array for readout of a virtually unlimited number of microarrays. A microarray based on an immunoassay for the detection of a mouse generic protein in a concentration range from 0.03 to 30 μg mL−1 was carried out to assess the performance of the electrical readout approach. A sigmoid response with a limit of detection of 0.1 μg mL−1 and a dynamic range of 1 order of magnitude was obtained. A comparative study was also carried out with two well established analytical procedures. First, the urease-based immunoassay was tested in a 96 well microtiter plate using phenol red pH indicator and absorbance detection. Second, the microarray was carried out using the same target protein concentration range but applying a Cy3 label and fluorescence detection. Both assays allowed for the validation of the performance of the presented electrical readout system.
Original languageEnglish
Pages (from-to)1726–1731
Number of pages6
JournalAnalytical Chemistry
Volume83
Issue number5
Early online date2 Feb 2011
DOIs
Publication statusPublished - 2011

Fingerprint

Microarrays
chutes
readout
transducers
immunoassay
proteins
Glass
Transducers
glass
Urease
Proteins
Assays
electrodes
Phenolsulfonphthalein
ureas
Readout systems
phenols
dynamic range
mice
hydrolysis

Keywords

  • microarray readout
  • impedimetric transducers
  • rease-based immunoassay

Cite this

Bonilla, D., Mallen, M., De La Rica, R., Fernandez-Sanchez, C., & Baldi, A. (2011). Electrical readout of protein microarrays on regular glass slides. Analytical Chemistry, 83(5), 1726–1731. https://doi.org/10.1021/ac102938z
Bonilla, Diana ; Mallen, Maria ; De La Rica, Roberto ; Fernandez-Sanchez, Cesar ; Baldi, Antoni. / Electrical readout of protein microarrays on regular glass slides. In: Analytical Chemistry. 2011 ; Vol. 83, No. 5. pp. 1726–1731.
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Bonilla, D, Mallen, M, De La Rica, R, Fernandez-Sanchez, C & Baldi, A 2011, 'Electrical readout of protein microarrays on regular glass slides', Analytical Chemistry, vol. 83, no. 5, pp. 1726–1731. https://doi.org/10.1021/ac102938z

Electrical readout of protein microarrays on regular glass slides. / Bonilla, Diana; Mallen, Maria; De La Rica, Roberto; Fernandez-Sanchez, Cesar; Baldi, Antoni.

In: Analytical Chemistry, Vol. 83, No. 5, 2011, p. 1726–1731.

Research output: Contribution to journalArticle

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Bonilla D, Mallen M, De La Rica R, Fernandez-Sanchez C, Baldi A. Electrical readout of protein microarrays on regular glass slides. Analytical Chemistry. 2011;83(5):1726–1731. https://doi.org/10.1021/ac102938z