Carbon dots-adorned silver nanoparticles as a straightforward sustainable colorimetric sensor for the rapid detection of ketotifen in eye drops and aqueous humor

The rapid and accurate detection of drug molecules in pharmaceutical formulations and biological samples is of paramount importance. In this research article, we present a novel colorimetric sensor based on carbon dots decorated silver nanoparticles (CDs/AgNPs) for the rapid detection of ketotifen (KTF), a widely used antihistamine drug. The CDs were synthesized via a facile one-step microwave-assisted method and subsequently conjugated onto AgNPs through a simple adsorption process, forming a stable CDs/AgNPs composite. The resulting composite exhibited unique optical properties, including a strong absorption peak at 410 nm with remarkable intensity reduction and color changes upon the addition of KTF. The developed colorimetric sensor exhibited a wide linear range of 3.0-40.0 µg mL-1 (R2 = 0.9996), with a %RSD of 2.41, and a low limit of detection (LOD) of 0.981 µg mL-1. Furthermore, the sensor's practical applicability was evaluated by successfully detecting KTF in eye drops and artificial aqueous humor, demonstrating a remarkable percentage recovery exceeding 96.0 %. Finally, a comprehensive evaluation of the greenness and blueness of the method was performed using analytical eco-scale, GAPI, AGREEprep, and BAGI tools. The results of these assessments indicate its exceptional sustainability. Overall, the proposed method holds significant potential for applications in pharmaceutical quality control and therapeutic monitoring, contributing to improved patient care and drug safety in the field of ophthalmology.