Determination of digoxin in serum samples using a flow-through fluorosensor based on a molecularly imprinted polymer

Area of Science:

• Analytical Chemistry
• Polymer Science
• Biomedical Engineering

Background:

• Development of selective recognition materials is crucial for accurate digoxin quantification.
• Molecularly imprinted polymers (MIPs) offer tailored binding sites for specific analytes.
• Previous bulk polymerization methods for MIPs required further optimization for sensor integration.

Purpose of the Study:

• To develop a competitive flow-through FIA assay for digoxin detection.
• To synthesize and characterize a highly selective MIP for digoxin recognition.
• To integrate the MIP into a spectrofluorimetric sensor for real-time analysis.

Main Methods:

• Photo-initiated polymerization was used to synthesize the optimal MIP with digoxin as the template.
• Soxhlet extraction removed the template, and the MIP was packed into a flow cell.
• Spectrofluorimetry was employed for reaction and detection, with optimization of physical and chemical variables.
• Non-imprinted polymer (NIP) binding was analyzed for comparison.

Main Results:

• The developed MIP-based fluorosensor demonstrated high selectivity and sensitivity for digoxin.
• A low detection limit of 1.7x10^-2 µg/mL and high reproducibility (R.S.D. < 1.77%) were achieved.
• No significant interference was observed from structurally analogous compounds at 100-fold higher concentrations.
• The sensor was successfully applied to determine digoxin levels in human serum samples.

Conclusions:

• A robust and selective flow-injection analysis assay for digoxin has been successfully developed using MIP technology.
• The MIP-based fluorosensor offers a promising tool for accurate and reliable digoxin monitoring in clinical diagnostics.
• The developed method overcomes limitations of previous MIP synthesis and demonstrates effective application in complex biological matrices.