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Updated: Jul 15, 2026
Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-α
Published on: June 14, 2018
Ultrasensitive densitometry detection of cytokines with nanoparticle-modified aptamers
Yuan-Yuan Li1, Chi Zhang, Bo-Sheng Li
1MOE Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
Background:
Aptamers mimic properties of antibodies and sometimes turn out to be even better than antibodies as reagents for assays. We describe the establishment of an ultrasensitive densitometry method for cytokine detection by nanoparticle (NP)-modified aptamers.
Methods:
The assay simultaneously uses a gold NP-modified aptamer and a biotin-modified aptamer to bind to the target protein, forming a sandwich complex. The absorbance signal generated by the aptamer-protein complex is amplified and detected with a microplate reader.
Results:
The assay for platelet-derived growth factor B-chain homodimer (PDGF-BB) was linear from 1 fmol/L to 100 pmol/L (R(2) = 0.9869). The analytical detection limit was 83 amol/L. The intraassay and interassay imprecision (CVs) was < or =7.5%. Serum concentrations of PDGF-BB determined with the gold NP-modified aptamer assay and with ELISA were not significantly different.
Conclusions:
The gold NP-modified aptamer assay provides a fast, convenient method for cytokine detection and improves the detection range and the detection limit compared with ELISA.
