A Novel Immunoprobe Strategy Integrating Tetrahedral DNA Nanostructure and Protein A for Sensitivity Enhancement: Application in Lead Ion Detection
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Published on: March 7, 2018
Xiaotong Hao1, Yangyang Li1, Zhengwei Zhu2
1College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
Insights
A new immunoprobe combining DNA nanostructures and protein A enhances antibody labeling for sensitive on-site food safety testing. This method improves detection of lead ions in immunochromatographic assays (ICAs).
Area of Science:
- Biotechnology
- Nanotechnology
- Analytical Chemistry
Background:
- Immunochromatographic assays (ICAs) are vital for on-site food safety detection.
- Challenges exist in maintaining immunoprobe bioactivity and efficient antibody labeling.
Purpose of the Study:
- To develop a novel immunoprobe for enhanced antibody immobilization and bioactivity.
- To apply this immunoprobe in an ICA for sensitive lead ion detection.
Main Methods:
- Integration of tetrahedral DNA nanostructure (TDN) with protein A (PrA) to create a novel immunoprobe.
- Utilizing TDN as a scaffold and PrA as a bridging ligand for oriented antibody immobilization.
- Application of the developed immunoprobe in an ICA for lead ion detection.
Main Results:
- The novel immunoprobe demonstrated superior antibody coupling efficiency and maintained antibody bioactivity.
- Compared to PrA or TDN alone, the combined approach showed higher affinity and a greater proportion of active antibodies.
- The ICA achieved a visual limit of detection (vLOD) of 0.05 ng/mL and a scanning limit of quantitation (sLOQ) of 0.031 ng/mL for lead ions.
Conclusions:
- The AuNP-TDN-PrA-mAb immunoprobe offers controllable antibody orientation and density for highly sensitive ICAs.
- This strategy significantly improves antibody labeling and bioactivity, addressing key challenges in ICA development.
- The developed ICA shows great potential for diverse, practical on-site detection applications in food safety.
Abstract:
Immunochromatographic assay (ICA) has been extensively utilized for on-site detection to ensure food safety. However, maintaining the bioactivity of immunoprobes while achieving efficient antibody labeling remains a significant challenge. In this study, a novel immunoprobe was developed by integrating tetrahedral DNA nanostructure (TDN) with protein A (PrA) and was subsequently applied in an ICA for the detection of lead ions. Notably, TDN served as a scaffold to enable a tailorable distribution of antibodies, while PrA acted as a bridging ligand to facilitate the oriented immobilization of antibodies. This strategy significantly enhanced the coupling efficiency of antibodies while maintaining their bioactivity. As expected, the proposed immunoprobe exhibited a higher affinity and a greater proportion of active antibodies compared to immunoprobes based solely on PrA or TDN. Moreover, the developed ICA achieved a visual limit of detection (vLOD) of 0.05 ng/mL and a scanning limit of quantitation (sLOQ) of 0.031 ng/mL for lead ions, respectively. By combining TDN and PrA, the AuNP-TDN-PrA-mAb immunoprobe enabled a controllable orientation and adjustable coverage density of antibodies. This unique property holds great potential for establishing a highly sensitive ICA, thereby meeting diverse detection requirements in practical applications.
