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Updated: May 28, 2026
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Fluorescent Lateral Flow Immunoassay Based on Quantum Dots Nanobeads
Published on: June 28, 2024
Simultaneous multi-biomarker detection: streptavidin-biotin mediated high-quality quantum dot immunosensor with
Huanhuan Xing1, Ruixue Zhang1, Ning Li1
1Henan International Joint Laboratory of Quantum Dot Materials, and School of Nanoscience and Materials Engineering, Henan University, Kaifeng, 475004, China.
Analytica Chimica Acta
|May 26, 2026
Summary
A novel dual-color quantum dot (QD) immunosensor enables simultaneous detection of prostate-specific antigen (PSA) and alpha-fetoprotein (AFP). This high-sensitivity assay significantly improves early cancer diagnosis by overcoming limitations of traditional multiplexed biomarker detection.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Analytical Chemistry
Background:
- Developing sensitive, high-throughput, multiplexed detection methods for tumor markers is crucial for early cancer diagnosis.
- Traditional streptavidin-biotin (SA-biotin) quantum dot (QD) immunoassays face challenges in simultaneous multi-biomarker detection within a single reaction.
- This study addresses limitations in multiplexed tumor marker detection.
Purpose of the Study:
- To design a highly sensitive, SA-biotin-mediated, dual-color QD fluorescence signal amplification immunosensor.
- To enable simultaneous detection of prostate-specific antigen (PSA) and alpha-fetoprotein (AFP) within a single microplate well.
- To overcome multiplexing constraints of traditional assays for improved clinical diagnostics.
Main Methods:
- Utilized SA-modified red and green QDs linked to biotin-PEG12-NHS ester-modified secondary antibodies (Ab2) to form dual-color QD-SA-bio-Ab2 probes.
- Leveraged high-affinity SA-biotin interaction and a long PEG spacer arm to enhance antibody loading and reduce steric hindrance.
- Optimized conditions for synergistic signal amplification.
Main Results:
- Demonstrated a wide linear range for both PSA and AFP (0.5 to 1000 ng/mL).
- Achieved limits of detection (LOD) of 0.25 ng/mL for PSA and 0.32 ng/mL for AFP, approximately 6-fold lower than standard dual-color QD immunosensors.
- Validated accuracy through recovery tests and clinical serum sample analysis, showing competitive results with prevalent testing technologies.
Conclusions:
- The dual-color QD-SA-bio-Ab2 probe offers a universal fluorescent platform overcoming multiplexing limitations of traditional assays.
- Combining high-performance QDs with a strategic PEG-spacer architecture provides a novel approach for fluorescence enhancement.
- Represents a significant advancement in achieving high-sensitivity, high-throughput multiplexed detection for clinical diagnostics.
