Quantum dots based potential-resolution dual-targets electrochemiluminescent immunosensor for subtype of tumor marker and its serological evaluation

Anal Chem. 2015 Sep 15;87(18):9163-9. doi: 10.1021/acs.analchem.5b02660. Epub 2015 Aug 25.

Abstract

The identification of subtypes of known tumor markers is of great importance for clinical diagnosis but still a great challenge in novel detection methodologies with simple operation and acceptable sensitivity. This work for the first time reported a quantum dots (QDs) based potential-resolved electrochemiluminescent (ECL) immunosensor to realize simultaneous detection of dual targets. Because of different surface microstructures, dimercaptosuccinic acid stabilized CdTe (DMSA-CdTe) QDs and TiO2 nanoparticles-glutathione stabilized CdTe (TiO2-GSH-CdTe) QDs composites showed a large difference of ECL peak potential (∼360 mV), which provided an access for potential-resolution detection. The ECL emission on indium tin oxide electrodes showed consistent strength during the cyclic scan, and intensity data were collected at -0.89 V and -1.25 V (vs Ag/AgCl) for DMSA-CdTe QDs and TiO2-GSH-CdTe QDs composites, respectively. The interface modification procedures of immunosensor construction were characterized by atomic force microscopy. The portion of Lens culinaris lectin affiliated isoform of alpha fetoprotein (AFP), AFP-L3%, in total AFP, is recently a novel criteria showing even higher sensitivity and specificity than AFP at the early stage of cancer. Combined with the enzyme cyclic amplification strategy, linear ranges for AFP-L3 and AFP dual-targets detection were 3.24 pg mL(-1)-32.4 ng mL(-1) and 1.0 pg mL(-1)-20 ng mL(-1), with limits of detection of 3.24 pg mL(-1) and 1.0 pg mL(-1), respectively. Compared with clinical detection data, the calculated portion of AFP-L3% by as-prepared immunosensor showed acceptable accuracy. These results open a new avenue for facile and rapid multiple-components detection based on the nano-ECL technique and provide a new clinical diagnosis platform for HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Immobilized / chemistry
  • Antibodies, Immobilized / immunology
  • Biomarkers, Tumor / blood*
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Blood Chemical Analysis / instrumentation
  • Blood Chemical Analysis / methods*
  • Cadmium Compounds / chemistry*
  • Electrochemistry
  • Electrodes
  • Glutathione / chemistry
  • Humans
  • Immunoassay / instrumentation
  • Immunoassay / methods*
  • Limit of Detection
  • Luminescent Measurements
  • Protein Isoforms / blood
  • Quantum Dots / chemistry*
  • Reproducibility of Results
  • Tellurium / chemistry*
  • Titanium / chemistry
  • alpha-Fetoproteins / analysis*

Substances

  • Antibodies, Immobilized
  • Biomarkers, Tumor
  • Cadmium Compounds
  • Protein Isoforms
  • alpha-Fetoproteins
  • titanium dioxide
  • Titanium
  • Glutathione
  • Tellurium
  • cadmium telluride