Warfarin Induced Quenching of the Carbon Quantum Dots: Mechanism Study and Warfarin Sensor Construction

The mechanism of the fluorescence quenching of the CQDs by warfarin was determined and based on this study a simple, low cost and highly sensitive nanosensor was developed for determination of Warfarin in plasma samples. The carbon quantum dots with 3.5 mu s lifetime (halflife of 2.4 mu s) were synthesized by hydrothermal method and characterized. The fluorescence rate constant of 4.5 x 10(4) s(-1) and quenching rate constant of 6.18 x 10(4) s(-1) (from 10 mu M warfarin that result in 17% lifetime reduction) was calculated. High quenching efficiency results in 21.63 L mmol(-1) Stern-Volmer constant and the study of pH and temperature also confirm the dynamic quenching mechanism. The second order rate constant of 6.18 x 10(4) L mmol(-1) s(-1) was obtained for collisions between CQDs and warfarin. Based on this mechanism, a simple, low cost and very sensitive warfarin nanosensor was developed with calibration sensitivity of 21.63 L mmol(-1), working range of 0.10 - 12.00 mu M and detection limit of 0.01 mu M.

Automated summary

The mechanism of fluorescence quenching of carbon quantum dots (CQDs) by warfarin was successfully determined and used to develop a simple, low cost, and highly sensitive nanosensor for detecting warfarin concentration. The nanosensor has high quenching efficiency and sensitivity, capable of detecting warfarin within the concentration range of 0.01 - 12.00 μM.