Competition-derived FRET-switching cationic conjugated polymer-Ir(III) complex probe for thrombin detection

Area of Science:

• Biochemistry
• Analytical Chemistry
• Materials Science

Background:

• Thrombin is a key enzyme in coagulation with implications for various diseases.
• Accurate and sensitive detection of thrombin is crucial for clinical diagnostics.
• Existing thrombin assay methods may lack sensitivity, specificity, or convenience.

Purpose of the Study:

• To develop a novel, label-free, and convenient strategy for quantitative thrombin detection.
• To utilize fluorescence resonance energy transfer (FRET) for sensitive thrombin quantification.
• To demonstrate the potential of the developed assay for clinical applications.

Main Methods:

• A FRET system was designed using a cationic conjugated polymer (CCP) as the energy donor and an Ir(III) complex as the acceptor.
• Thrombin aptamers were introduced to modulate the FRET process through specific binding interactions.
• The assay principle relies on the disruption and subsequent restoration of FRET upon thrombin binding.

Main Results:

• The developed assay achieved highly sensitive thrombin detection down to approximately 0.05 pM.
• The assay demonstrated excellent specificity, distinguishing thrombin from other proteins.
• The FRET-based strategy showed successful application in diluted real urine and serum samples with satisfactory recovery.

Conclusions:

• A novel and convenient label-free assay for sensitive thrombin detection was successfully developed.
• The FRET-based strategy offers high sensitivity and specificity, with potential for aptamer-structure-independent target detection.
• The assay's applicability in biological samples highlights its significant potential for rapid clinical diagnosis.