Intra-Mesopore Immunoassay Based on Core-Shell Structured Magnetic Hierarchically Porous ZIFs

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Quantifying low-abundance blood biomarkers is critical for early disease detection but remains challenging.
• Existing immunoassay methods often lack the required sensitivity for femtomolar-level detection.

Purpose of the Study:

• To develop a highly sensitive analytical model for quantifying low-abundance biomarkers in blood.
• To create an innovative nanoparticle structure for enhanced immunoassay performance.

Main Methods:

• Fabrication of a superparamagnetic core-shell structure (Fe3O4@HPZIF-8) using soft-template self-assembly and confinement growth.
• Development of an intra-mesopore immunoassay (IMIA) leveraging the Fe3O4@HPZIF-8 nanostructure for antibody immobilization and magnetic separation.
• Clinical validation using Cardiac Troponin I (cTnI) detection in human serum samples from acute myocardial infarction (AMI) patients.

Main Results:

• The Fe3O4@HPZIF-8 nanostructure facilitated high antibody coating density and efficient antigen capture.
• The IMIA demonstrated femtomolar-level detection capabilities, significantly enhancing sensitivity.
• A >100-fold improvement in the limit of detection (LOD) was achieved compared to traditional ELISA for cTnI detection.

Conclusions:

• The developed IMIA, utilizing Fe3O4@HPZIF-8 nanoparticles, offers a powerful and sensitive platform for biomarker quantification.
• This technology provides a significant advancement for early disease diagnosis, exemplified by its application in detecting acute myocardial infarction.
• The IMIA platform's adaptability through antibody modification suggests broad applicability for various diagnostic biomarkers.