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Potentiometric immunoassay with quantum dot labels.
Journal article

Potentiometric immunoassay with quantum dot labels.

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  • 2007-05-29
Published in:
  • Analytical chemistry. - 2007
Animals
Cadmium Compounds
Electrochemistry
Hydrogen Peroxide
Hydrogen-Ion Concentration
Immunoassay
Immunoglobulin G
Ion-Selective Electrodes
Mice
Quantum Dots
Selenium Compounds
Sensitivity and Specificity
Sodium
English Potentiometric sensors based on polymer membrane electrodes, if properly optimized, are useful for measurements at trace levels. The expected independence of the electrochemical signal of the sample size makes them extremely attractive for measurements in small volumes. Here, we report on electrodes for the potentiometric detection of cadmium ions that reach a detection limit of 6 nM and utilize a Na(+)-selective electrode as pseudoreference in order to facilitate measurements in 150-microL samples. A potentiometric immunoassay of mouse IgG is performed via CdSe quantum dot labels on a secondary antibody according to a sandwich immunoassay protocol in a microtiter plate format. The CdSe quantum dots are found to be easily dissolved/oxidized in a matter of minutes with hydrogen peroxide, allowing us to maintain the pH at a near-neutral value. The potentiometric protein immunoassay exhibits a log-linear response ranging from 0.15 to 4.0 pmol of IgG, with a detection limit of <10 fmol in 150-microL sample wells.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/123621
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