Conformation-sensitive antibody-based point-of-care immunosensor for serum Ca(2+) using two-dimensional sequential...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biochemistry

Background:

• Calcium homeostasis is crucial for physiological functions.
• Current methods for measuring ionic calcium can be complex and time-consuming.
• Developing rapid and accurate diagnostic tools is essential for clinical practice.

Purpose of the Study:

• To develop a rapid immunosensor for ionic calcium (Ca2+) analysis.
• To overcome limitations of existing lateral flow assays for calcium detection.
• To create a system for simplified and potentially simultaneous diagnostic testing.

Main Methods:

• Utilized a membrane chromatographic technique with a monoclonal antibody sensitive to calcium-binding protein (CBP) conformational changes.
• Developed a two-dimensional chromatographic format to circumvent tracer migration issues.
• Employed a smartphone-based detector for signal measurement, achieving results within 15 minutes.

Main Results:

• The developed immunosensor accurately measured ionic calcium within the clinical dynamic range (0.25-2.5mM).
• Analytical performance showed high correlation with the reference system (i-STAT).
• The novel method successfully addressed non-specific interactions affecting tracer migration.

Conclusions:

• The rapid immunosensor provides an efficient method for assessing calcium homeostasis.
• The technology simplifies diagnostic protocols and holds potential for dual-immunoassay development.
• This advancement could significantly improve the diagnosis and management of calcium-related disorders.