Versatile Immunosensor Using CdTe Quantum Dots as Electrochemical and Fluorescent Labels

• Published in: Analytical chemistry (Washington) Vol. 79; no. 22; pp. 8494 - 8501
• Main Authors: Cui, Rongjing, Pan, Hong-Cheng, Zhu, Jun-Jie, Chen, Hong-Yuan
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.11.2007
• Subjects: Analytical chemistry; Antibodies - chemistry; Antibodies - immunology; Cadmium Compounds - chemistry; Chemistry; Electric Impedance; Electrochemical methods; Electrochemistry; Exact sciences and technology; Fluorescence; Fluorescent Dyes - chemistry; General, instrumentation; Humans; Immunoassay; Immunoassay - methods; Microscopy, Atomic Force; Miscellaneous; Nanoparticles; Quantum Dots; Sensitivity and Specificity; Sensors; Tellurium - chemistry; Tin Compounds - chemistry; Monolayer; Gold; Quantum dot; Chemical analysis; Stability; Electrochemical method; Nanoparticle; Voltammetry; Chemical sensor; Indium oxide; Immunosensor; Protein; Immunological method; Sensitivity; Reproducibility; Biosensor; Imaging; Tin oxide; Cadmium tellurides; Simultaneous measurement; Comparative study
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac070923d

A versatile immunosensor using CdTe quantum dots as electrochemical and fluorescent labels has been developed for sensitive protein detection. This sandwich-type sensor is fabricated on an indium tin oxide chip covered with a well-ordered gold nanoparticle monolayer. Gel imaging systems were successfully introduced to develop a novel high-efficient optical immunoassay, which could perform simultaneous detection for the samples with a series of different concentrations of a target analyte. The linear range of this assay was between 0.1 and 500 ng/mL, and the assay sensitivity could be further increased to 0.005 ng/mL with the linear range from 0.005 to 100 ng/mL by stripping voltammetric analysis. The immunosensor showed good precision, high sensitivity, acceptable stability, and reproducibility and could be used for the detection of real sample with consistent results in comparison with those obtained by the ELISA method.