Boron nitride quantum dot-based fluorescent sensor for carbamazepine determination in exhaled breath condensate

Carbamazepine is a widely prescribed antiepileptic drug with a narrow therapeutic index, necessitating precise monitoring to avoid toxicity and ensure therapeutic efficacy. This study presents a fluorescence-based nanosensor using boron nitride quantum dots (BNQDs) for the rapid and sensitive detection of carbamazepine in exhaled breath condensate (EBC). BNQDs were prepared via a simple hydrothermal technique and characterized using transmission electron microscopy, dynamic light scattering, energy-dispersive X-ray, and attenuated total reflectance-Fourier transform infrared techniques. The sensor exhibited a concentration-dependent quenching of BNQD fluorescence upon carbamazepine addition, with a linear response range of 0.2-2.4 μg mL^-1 and a low detection limit of 0.05 μg mL^-1. Stern-Volmer analysis confirmed a dynamic quenching mechanism. The nanosensor also demonstrated high selectivity against common co-administered drugs and was successfully applied to real EBC samples collected from patients receiving carbamazepine therapy. This BNQD-based sensing platform offered a rapid, cost-effective, and user-friendly approach for the non-invasive therapeutic drug monitoring of carbamazepine.