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

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.

• Authors: Xuan Liu, Hui Jiang, Yuan Fang, Wei Zhao, Nianyue Wang, Guizhen Zang
• Journal: Analytical chemistry (Anal Chem) Vol. 87 Issue 18 Pg. 9163-9 (Sep 15 2015) ISSN: 1520-6882 [Electronic] United States
• PMID: 26291342 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

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