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Polystyrene microspheres based sandwich immunosensor using CdTe nanoparticles amplification and ultrasensitive
Shamsa Kanwal1, Zoumama Traore, Xingguang Su
1Department of Analytical Chemistry, College of Chemistry, Jilin University, Qianjin Street, Changchun 130012, China.
Insights
A novel sandwich immunoassay using polystyrene microspheres and CdTe nanoparticles offers sensitive detection of human-immunoglobulin G (HIgG). This method achieves a low detection limit, showing promise for various biological analyses.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Nanotechnology
Background:
- Accurate detection of human-immunoglobulin G (HIgG) is crucial for diagnosing various conditions.
- Existing immunoassay methods may require complex instrumentation or lack sufficient sensitivity.
- Development of sensitive and specific detection methods is an ongoing challenge in biomedical diagnostics.
Purpose of the Study:
- To develop a highly sensitive and specific sandwich immunoassay for human-immunoglobulin G (HIgG).
- To utilize polystyrene microspheres and cadmium telluride nanoparticles (CdTeNPs) for enhanced detection.
- To establish a reliable and potentially cost-effective method for protein immune-detection.
Main Methods:
- A sandwich immunoassay format was designed using polystyrene microspheres (PS) as the immobilizing support.
- Primary anti-HIgG (Ab1) was immobilized on PS via electrostatic interaction.
- Horseradish peroxidase-labeled secondary anti-HIgG (Ab2) was conjugated to CdTe nanoparticles (CdTeNPs) via covalent binding.
- Chemiluminescence (CL) detection was employed for signal generation and amplification.
Main Results:
- The developed immunoassay demonstrated a broad linear response range for HIgG from 0.01 to 300 ng mL(-1).
- An extremely low detection limit of 0.3 pg mL(-1) was achieved, indicating high sensitivity.
- The assay showed good reliability when compared to the standard enzyme-linked immunosorbent assay (ELISA).
Conclusions:
- The proposed sandwich immunoassay using PS and CdTeNPs offers a sensitive, accurate, and instrumentally simple method for HIgG detection.
- This technique holds significant promise for protein immune-detection, DNA analysis, and other biological applications.
- The combination of CL detection and nanoparticle-based signal amplification provides a powerful tool for sensitive biomolecule quantification.
Abstract:
In this paper we propose a specific sandwich immunoassay method for human-immunoglobulin G (HIgG). This immunoassay protocol takes advantage of sandwich binding of primary and secondary antibodies for increased specificity. Polystyrene microspheres (PS) serve as immobilizing support, site for sandwich immunoassay and then subsequently used for chemiluminescence (CL) detections. In this sandwich immunoassay, PS microspheres were modified with the primary anti-HIgG (Ab1) via electrostatic interaction, while CdTe nanoparticles (CdTeNPs) were modified with horseradish peroxidase labeled anti-HIgG (Ab2) via covalent binding. Antigen HIgG (Ag) was specifically captured by the first and secondary antibody and form sandwich immunoassay format. Combination of the remarkable sensitivity of CL method and the use of CdTe NPs as anti-HIgG-HRP carrier for the enzymatic signal amplification, provide a linear response range of HIgG from 0.01 to 300 ng mL(-1) with an extremely low detection limit of 0.3 pg mL(-1). This immunoassay system has many desirable merits including sensitivity, accuracy, and little required instrumentation. The assay results were compared with enzyme-linked immunosorbent assay (ELISA), and showed relatively good reliability. Significantly the new protocol may become quite promising technique for protein immune-detection as well as DNA analysis and other biological analyses.
