Validation of a Novel Potentiometric Method Based on a Polymeric PVC Membrane Sensor Integrated with Tailored Receptors for the Antileukemia Drug Cytarabine

"Off/On" Fluorescent Probe based on Aggregation-Induced Quenching of ZnO-Quantum dots for Determination of Ara-C: Pharmacokinetic Applications, Adsorption Kinetics & Green Profile Assessment

Herein, a turn "Off/On" fluorescence probe based on ZnO quantum dots (ZnO-QDs) has been proposed and successfully utilized for the determination of Ara-C (cytarabine) using ceric ions (Ce4+) as quencher and ethylenediamine (ED) as a linker. The probe is based initially on the quenching effect of Ce4+ ions on the strong native fluorescence of ZnO-QDs forming the Turn Off system (Ce@ZnO-QDs) that believed to occur due to the aggregation-induced quenching (AIQ) mechanism. The second step is the addition of Ara-C in the presence of ethylenediamine (ED) that encourages the formation of Ara-C/ED/Ce4+ as well as the release of the free ZnO-QDs, leading to the recovery of the fluorescence intensity. The developed sensing platform shows a linear response towards Ara-C over the range of 10 to 1000 ng mL-1 giving a limit of detection (LOD) and limit of quantitation (LOQ) of 1.22 ng mL-1 and 3.70 ng mL-1, respectively. A dispersive magnetic solid phase micro-extraction (dMSPE) method was developed and optimized for the extraction of Ara-C in spiked human plasma using thiol-modified magnetite nanoparticles (S-MNPs). The proposed platform exhibits good sensitivity toward Ara-C in the presence of different interfering substances. Excellent recoveries are obtained after spiking different concentrations of Ara-C into rabbit plasma samples. The validated experimental parameters have been successfully applied to monitor the pharmacokinetic profile of Ara-C in rabbit plasma. A detailed adsorption kinetics study has been carried out to provide a deep insight into the adsorption behavior of Ara-C on the thiol-doped-magnetite nanoparticles. The greenness assessment of the proposed method was achieved and compared with other reported methods using two tools of greenness; the green analytical procedure index (GAPI) and the analytical greenness calculator AGREE.

Biomimetic Sensors to Detect Bioanalytes in Real-Life Samples Using Molecularly Imprinted Polymers: A Review

Molecularly imprinted polymers (MIPs) come with the promise to be highly versatile, useful artificial receptors for sensing a wide variety of analytes. Despite a very large body of literature on imprinting, the number of papers addressing real-life biological samples and analytes is somewhat limited. Furthermore, the topic of MIP-based sensor design is still, rather, in the research stage and lacks wide-spread commercialization. This review summarizes recent advances of MIP-based sensors targeting biological species. It covers systems that are potentially interesting in medical applications/diagnostics, in detecting illicit substances, environmental analysis, and in the quality control of food. The main emphasis is placed on work that demonstrates application in real-life matrices, including those that are diluted in a reasonable manner. Hence, it does not restrict itself to the transducer type, but focusses on both materials and analytical tasks.

Applications of Potentiometric Sensors for the Determination of Drug Molecules in Biological Samples

Potentiometry is extensively studied by researchers as one of the electrochemical methods due to its multiple advantages. Until today, thousands of potentiometric sensors have been developed and applied successfully in many fields such as medicine, environmental monitoring, agriculture, industry and pharmaceutical sciences. Clinical drug analyses and determination of drugs in biological samples are highly important from a medical point of view. These analyses are carried out using various analytical devices including potentiometric sensors. These potentiometric sensors are superior to other devices in terms of several performance parameters, and thus present a good alternative for researchers. Using potentiometric sensors, very successful results in the identification of drug molecules in body fluids have been obtained and reported in the literature up to now. In this study, we review potentiometry-based sensors developed for the determination of drug molecules in various biological samples such as blood serum and urine, and touch upon their performance features in these applications.