Microchimica Acta

, Volume 178, Issue 3, pp 323–330

Electrodeposition of CdSe quantum dots and its application to an electrochemiluminescence immunoassay for α-fetoprotein

Original Paper

DOI: 10.1007/s00604-012-0844-z

Cite this article as:
Peng, S. & Zhang, X. Microchim Acta (2012) 178: 323. doi:10.1007/s00604-012-0844-z

Abstract

We report on the first label-free electrochemiluminescence (ECL) immunosensor for α-fetoprotein (AFP). It is based on the use of CdSe quantum dots that were electrodeposited directly on a gold electrode from an electrolyte (containing cadmium sulfate, EDTA and selenium dioxide) by cycling the potential between 0 and -1.2 V (vs. SCE) for 60 s. The electrodeposited dots were characterized by scanning electron microscopy and energy dispersive spectroscopy. Under optimal conditions, the specific immunoreaction between AFP and anti-AFP resulted in a decrease of the ECL signal because of the steric hindrance and the transfer inhibition by peroxodisulfate. The quenching effect of the immunoreaction on the intensity of the ECL was used to establish a calibration plot which is linear in the range from 0.05 to 200 ng mL−1. The detection limit is 2 pg mL−1. The assay is highly sensitive and satisfactorily reproducible. In our opinion it opens new avenues to apply ECL in label-free biological assays.

https://static-content.springer.com/image/art%3A10.1007%2Fs00604-012-0844-z/MediaObjects/604_2012_844_Figa_HTML.gif
Figure

We report on the first label-free electrochemiluminescence (ECL) immunosensor for α-fetoprotein (AFP). It is based on the use of CdSe quantum dots that were electrodeposited directly on a gold electrode from an electrolyte. Under optimal conditions, the specific immunoreaction between AFP and anti-AFP resulted in a decrease of the ECL signal because of the steric hindrance and the transfer inhibition by peroxodisulfate

Keywords

BiosensorCdSeElectrochemiluminescenceElectrodepositionImmunoassay

Supplementary material

604_2012_844_MOESM1_ESM.doc (116 kb)
ESM 1(DOC 116 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.School of Chemistry and Chemical EngineeringShandong UniversityJinanChina