Spectrophotometric study of ketoconazole binding with citrate capped silver nanoparticles and its monitoring in human plasma samples.

Ketoconazole or Nizoral is an antifungal medication used to treat various type of fungal infections. It has been reported that this antifungal agent is able to induce a variety of heart function side effects, such as long-QT syndrome, and ventricular arrhythmias. Hence, prescribing, identifying and controlling the side effects of medications such as ketoconazole is essential for human safety. In this study, a distinct and fast colorimetric probe based on citrate capped silver nanoparticles (Cit-AgNPs) was introduced for determination of trace amounts of ketoconazole. Cit-AgNPs were synthesized trough a novel method and applied for the quantification of ketoconazole in human plasma samples. Ultraviolet-visible spectroscopy, transmission electron microcopy, dynamic light scattering, and energy dispersive X-ray spectroscopy analysis, have been utilized for characterization of Cit-AgNPs. It was revealed that in the presence of ketoconazole, the absorption intensity of Cit-AgNPs was decreased by increasing the ketoconazole concentration. Moreover, this reaction is accompanied by a color change from shiny yellow to brown/red in acidic pH. Under acidic pH and optimum condition, the calibration graph of the assay was linear in the range of 0.1 to 0.8 μM. According to the obtained results Cit-AgNPs can be used as a novel probe for the sensitive and specific detection and determination of similar drugs in clinical samples. Also, this method open a new way to biomedical analyses of pharmaceutical samples which is necessary in TDM.