Herein, a novel ‘‘turn on’’ ion-imprinted chemosensor for highly sensitive and selective detection of Al3+ ions in complex matrices has been developed. The method was based on using chitosan (CHIT) biopolymer/magnetite nanoparticles (MGNPs) functionalized with 8-hydroxyquinoline sulfonic acid (8-HQS) in the presence of Al3+ ions to synthesize a magnetite ion non-imprinted biopolymer (MGINIBP) chemosensor. This newly developed chemosensor was synthesized via polymerization of CHIT with [3-(2,3-epoxypropoxy)-propyl]trimethoxysilane [EPPTMS] in the presence of magnetite nanoparticles, 8-HQS, and an Al3+ ion template. The template was then removed from the sensor using 0.5 M NaF to form new recognition sites for Al3+. The newly developed chemosensor was termed as a magnetite ion-imprinted biopolymer (MGIIBP). Exposure of Al3+ ions to the developed system embedded with 8-HQS resulted in the formation of a fluorescent polymer, and emission maximum was obtained at 500 nm after excitation at 365 nm. Furthermore, with the increasing Al3+ ion concentration, the fluorescence intensity increases within the range 0.081–9.0  108 M with a limit of detection (LOD) of 0.027  108 M. In addition, the synthesized chemosensor was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier-transform infrared spectroscopy (FTIR). The proposed MGIIBP sensor was successfully applied to the determination of Al3+ ions in water and human serum samples as model examples of complex natural matrix media.

Herein, a novel ‘‘turn on’’ ion-imprinted chemosensor for highly sensitive and selective detection of Al3+ ions in complex matrices has been developed. The method was based on using chitosan (CHIT) biopolymer/magnetite nanoparticles (MGNPs) functionalized with 8-hydroxyquinoline sulfonic acid (8-HQS) in the presence of Al3+ ions to synthesize a magnetite ion non-imprinted biopolymer (MGINIBP) chemosensor. This newly developed chemosensor was synthesized via polymerization of CHIT with [3-(2,3-epoxypropoxy)-propyl]trimethoxysilane [EPPTMS] in the presence of magnetite nanoparticles, 8-HQS, and an Al3+ ion template. The template was then removed from the sensor using 0.5 M NaF to form new recognition sites for Al3+. The newly developed chemosensor was termed as a magnetite ion-imprinted biopolymer (MGIIBP). Exposure of Al3+ ions to the developed system embedded with 8-HQS resulted in the formation of a fluorescent polymer, and emission maximum was obtained at 500 nm after excitation at 365 nm. Furthermore, with the increasing Al3+ ion concentration, the fluorescence intensity increases within the range 0.081–9.0  108 M with a limit of detection (LOD) of 0.027  108 M. In addition, the synthesized chemosensor was characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier-transform infrared spectroscopy (FTIR). The proposed MGIIBP sensor was successfully applied to the determination of Al3+ ions in water and human serum samples as model examples of complex natural matrix media.

Herein, a novel ultrasensitive molecularly imprinted sensor (MIS) for selective determination of a new direct acting anti-HCV velpatasvir (VELPR) was developed and fabricated for the first time. The fabricated MIS based on modification of a glassy carbon electrode (GCE) with multi-walled carbon nanotubes-gold nanoparticles (MWCNTs-AuNPs) composite after deposition on electro-synthesized 3D starfish like hollow nickel skeleton (3D SH-Ni S) to increase conductivity and effective surface area of MIS to amplify its signal. After that, the electrode was coated with molecularly imprinted polymer (MIP) by in situ electro-polymerization forming cavity with specific affinity and natural binding sites to VELPR. Differential pulse voltammetry (DPV) was used for selective detection of VELPR in complex matrices whereas, scanning electron microscope (SEM) and cyclic voltammetry (CV) were employed to characterize the fabricated sensor. All experimental factors concerning fabrication and chemical sensing properties were carefully studied and optimized. Under the optimized variables, the fabricated sensor exhibited excellent DPV response to VELPR over the range of 0.649–80.0 ng mL−1 with LOD of 0.21 ng mL−1. In addition to high sensitivity and selectivity, the sensor response to VELPR was highly reproducible and stable. Moreover, the fabricated sensor was successfully applied for the determination of VELPR in complex biological matrices and pharmaceutical tablets.

Herein, a novel ultrasensitive molecularly imprinted sensor (MIS) for selective determination of a new direct acting anti-HCV velpatasvir (VELPR) was developed and fabricated for the first time. The fabricated MIS based on modification of a glassy carbon electrode (GCE) with multi-walled carbon nanotubes-gold nanoparticles (MWCNTs-AuNPs) composite after deposition on electro-synthesized 3D starfish like hollow nickel skeleton (3D SH-Ni S) to increase conductivity and effective surface area of MIS to amplify its signal. After that, the electrode was coated with molecularly imprinted polymer (MIP) by in situ electro-polymerization forming cavity with specific affinity and natural binding sites to VELPR. Differential pulse voltammetry (DPV) was used for selective detection of VELPR in complex matrices whereas, scanning electron microscope (SEM) and cyclic voltammetry (CV) were employed to characterize the fabricated sensor. All experimental factors concerning fabrication and chemical sensing properties were carefully studied and optimized. Under the optimized variables, the fabricated sensor exhibited excellent DPV response to VELPR over the range of 0.649–80.0 ng mL−1 with LOD of 0.21 ng mL−1. In addition to high sensitivity and selectivity, the sensor response to VELPR was highly reproducible and stable. Moreover, the fabricated sensor was successfully applied for the determination of VELPR in complex biological matrices and pharmaceutical tablets.

An innovative spectrofluorometric method was developed for the analysis of a recently FDA approved anti-hepatitis C velpatasvir (VELP). The developed method was relied on dispersive solid phase extraction (dSPE) using synergistic effect of reduced graphene oxide (RGO) and cobalt hydroxide nanoparticles (CHNPs) in addition to cloud point extraction (CPE) using polyethylene glycol 6000 (PEG 6000) as non-ionic surfactant. This method combines the merits of preconcentration and interferences elimination achieved by dSPE and CPE, respectively. All relevant parameters such as surfactant concentration, ionic strength, pH, incubation time and others were thoroughly investigated and optimized. Fluorometric detection of VELP was carried out at excitation wavelength of 350 nm and emission wavelength of 415 nm. Under the optimum conditions, a linear calibration curve was achieved in the range of 0.5–45 ng mL−1. Limits of detection (LOD) and quantification (LOQ) based on three and ten times the standard deviation of the blank were 0.040 and 0.112 ng mL−1, respectively. This method was successfully applied for determination of VELP in real samples such as tablets, human plasma and urine samples with good recoveries.

An innovative spectrofluorometric method was developed for the analysis of a recently FDA approved anti-hepatitis C velpatasvir (VELP). The developed method was relied on dispersive solid phase extraction (dSPE) using synergistic effect of reduced graphene oxide (RGO) and cobalt hydroxide nanoparticles (CHNPs) in addition to cloud point extraction (CPE) using polyethylene glycol 6000 (PEG 6000) as non-ionic surfactant. This method combines the merits of preconcentration and interferences elimination achieved by dSPE and CPE, respectively. All relevant parameters such as surfactant concentration, ionic strength, pH, incubation time and others were thoroughly investigated and optimized. Fluorometric detection of VELP was carried out at excitation wavelength of 350 nm and emission wavelength of 415 nm. Under the optimum conditions, a linear calibration curve was achieved in the range of 0.5–45 ng mL−1. Limits of detection (LOD) and quantification (LOQ) based on three and ten times the standard deviation of the blank were 0.040 and 0.112 ng mL−1, respectively. This method was successfully applied for determination of VELP in real samples such as tablets, human plasma and urine samples with good recoveries.

In vitro drug release kinetics studies are routinely performed to examine the ability of new drug formulations to modulate drug release. The underlying assumption is that the studies are performed in a sufficiently dilute solution, where the drug release is not limited by the solubility and the difference in release kinetics profile reflects the performance of a drug carrier in vivo. This condition is, however, difficult to meet with poorly water-soluble drug formulations, as it requires a very large volume of release medium relative to the formulation mass, which makes it challenging to measure the drug concentration accurately. These difficulties are aggravated with nanoparticle (NP) formulations, which are hard to separate from the release medium and thus require a dialysis bag or repeated high-speed centrifugation for sampling. Perhaps for these reasons, drug release kinetics studies of NPs of poorly water-soluble drugs are often performed in suboptimal conditions in which the NPs are not sufficiently diluted. However, such a practice can potentially underestimate drug release from NPs, leading to an inaccurate prediction that the NPs will attenuate the drug activity in vivo. Here we perform release kinetics studies of two different NP formulations of paclitaxel, a representative poorly water-soluble drug, according to common practices in the literature. We find that the drug release from NPs can be substantially underestimated depending on the choice of the release medium, NP/medium ratio, and handling of release samples. We discuss potential consequences of underestimating drug release, ending with suggestions for future studies with NP formulations of poorly water-soluble drugs.

The hepatoprotective activity of the different extracts of Ficus sycomorus L. (FS) against N nitrosodiethylamine (NDEA) and CCl4-induced hepatocarcinogenesis (HCC) in rats has been investigated for the first time. Histological observations of liver tissues demonstrated that, both wood (FSWE) and leaf extracts (FSLE) possess significant hepatoprotective activity and stem bark extract (FSBE) shows moderate activity while fruit extract (FSFE) is not significantly effective.

The hepatoprotective activity of the different extracts of Ficus sycomorus L. (FS) against N nitrosodiethylamine (NDEA) and CCl4-induced hepatocarcinogenesis (HCC) in rats has been investigated for the first time. Histological observations of liver tissues demonstrated that, both wood (FSWE) and leaf extracts (FSLE) possess significant hepatoprotective activity and stem bark extract (FSBE) shows moderate activity while fruit extract (FSFE) is not significantly effective.

The hepatoprotective activity of the different extracts of Ficus sycomorus L. (FS) against N nitrosodiethylamine (NDEA) and CCl4-induced hepatocarcinogenesis (HCC) in rats has been investigated for the first time. Histological observations of liver tissues demonstrated that, both wood (FSWE) and leaf extracts (FSLE) possess significant hepatoprotective activity and stem bark extract (FSBE) shows moderate activity while fruit extract (FSFE) is not significantly effective.