Development of a metal-organic framework-based nanosensor for determination of cyclosporine in plasma samples

According to the narrow therapeutic range and multiple adverse effects of cyclosporine and the need for its therapeutic drug monitoring (TDM), in this study, an efficient zeolitic imidazolate framework-8 metal-organic framework (ZIF-8 MOF) based nanoprobe was designed for simple, rapid and high sensitive its quantification in plasma samples. After the successful synthesis of the ZIF-8 MOF, under the optimum condition, the fluorescence emission of ZIF-8 MOF, measured at an excitation wavelength of 370 nm and an emission wavelength of 417 nm, was enhanced with increasing cyclosporine concentration, due to the specific interactions between cyclosporine and the nanoprobe, including hydrogen bonding and hydrophobic effects. The nanoprobe showed a linear correlation between the analytical response and cyclosporine concentration in the concentration range of 0.01-1.0 µg mL^{- 1}, with a detection limit of 0.003 µg mL^{- 1}. Acceptable precision was achieved, evidenced by intra-day and inter-day relative standard deviations of 0.4% and 0.5%, respectively. Recovery between 97.1% and 102.1% in plasma samples indicated the method's reliability in practical applications.