Plastic ELISA-on-a-Chip Based on Sequential Cross-Flow Chromatography
| Autor: | Se-Hwan Paek, Seung-Mok Han, Il-Hoon Cho, Joung-Hwan Cho, Eui-Hwan Paek |
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| Rok vydání: | 2006 |
| Předmět: |
Time Factors
Capillary action Antibody Affinity Protein Array Analysis Analytical chemistry Enzyme-Linked Immunosorbent Assay Sensitivity and Specificity Signal Horseradish peroxidase Antibodies Analytical Chemistry Immunoenzyme Techniques Humans System on a chip Horseradish Peroxidase Detection limit Chromatography biology Chemistry Troponin I Substrate (chemistry) Chip Amperometry biology.protein Colorimetry |
| Zdroj: | Analytical Chemistry. 78:793-800 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/ac051453v |
| Popis: | A plastic chip that can perform immunoassays using an enzyme as signal generator, i.e., ELISA-on-a-chip, was developed by incorporating an immunostrip into channels etched on the surfaces of the chip. To utilize an analytical concept of cross-flow chromatography, the chip consisted of two cross-flow channels in the horizontal and vertical directions. In the vertical channel, we placed a 2-mm-wide immunostrip for cardiac troponin I (cTnI), which was identical to a conventional rapid test kit except for the utilization of an enzyme, horseradish peroxidase (HRP), as tracer. An enzyme substrate supply channel and a horizontal flow absorption pad compartment were transversely arranged on each lateral side of the signal generation pad of the strip, respectively. Upon application of a sample containing cTnI, it migrated vertically through the membrane strip by capillary action, and antigen-antibody binding occurred. After 15 min, the horizontal flow was initiated by the addition of a chromogenic substrate solution for HRP into the supply channel and by partial superimposition of the horizontal flow absorption pad onto the signal generation pad. A color signal proportional to the analyte concentration was produced on this pad, measured after 5 min as optical densities using a digital camera-based detector, and quantified by integration of the densities under the peak after normalization. Its calibration curve indicated that the detection limit of the chip was approximately 0.1 ng/mL and its quantification limit was 0.25 ng/mL. In measuring blindly prepared samples, the chip performance correlated with that of a reference system, Beckman Coulter Access, within 2.5-fold discrepancy at the detection limit. |
| Databáze: | OpenAIRE |
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