Molecularly-imprinted polymer-base bulk optode for the determination of ivabradine hydrochloride in Procoralan®

PVC membrane bulk optode incorporating 4-nitrobenzo-15-crown-5 and sodium tetrakis(1-imidazolyl) borate for the pico-molar determination of silver ion in pharmaceutical formulation

Silver ion (Ag+) is of harmful effects to both environment and human health. Ag+ soluble compounds and salts is used in treating mental illness, epilepsy, nicotine addiction, gastroenteritis, and infectious diseases, including syphilis and gonorrhea, and as anti-infective dermatological agent for controlling nose bleeding. However, high Ag+ doses cause several harmful effects to human health such as irreversible pigmentation of skin and eye, and problems to liver and kidney. A bulk membrane Optode is proposed in this work to measure the Ag+ concentration in the pharmaceutical formulations. The membrane optode is prepared from the ionophore 4-nitobenzo-15-crown-5, the ion-exchanger sodium tetrakis (imidazolyl) borate, the plasticizer o-nitrophenyl octyl ether, and the chromoionophore ETH 5294; these components are dissolved in the PVC/THF slurry to form the membrane. The optode is studied by atomic force microscope and UV-visible spectrophotometer, and its spectrum exhibits two maximum wavelengths of 550 and 665 nm, and response for Ag+ at these maximum wavelengths is reproducible in the concentration range of 10-11 to 10-8 M using acetate buffer of pH 5.0, with very low detection limit of 8.8 × 10-12 M. The most important feature in this work is the selectivity improvement for Ag+ over all interfering ions; the selectivity coefficient logarithmlogK A g + , c a t i o n opt is found to be - 4.3 for Cu2+, - 5.6 for Ni2+ and - 5.0 for Cd2+. The response mechanism is studied by FTIR, and it depends on ion-exchange of Ag+ and sodium imidazolyl borate, followed by the host-guest complexation between Ag+ and the crown ionophore, which is accompanied by concomitant deprotonation of the chromoionphore. The optode has a response time of 2-3 min within lifetime of 10 days with the same response. The optode can be applied successfully for Ag+ determination in the pharmaceutical formulation, PinkEye Relief® eye drop, which is used for treating inflammation, redness and water discharge of the eye; the high recovery and low standard deviation of the results using calibration curve method confirm the accuracy and precision of the proposed optode for its application in real samples.

Innovations in ion-selective optodes: a comprehensive exploration of modern designs and nanomaterial integration

In recent years, ion-selective optodes (ISOs) have remarkably progressed, driven by innovative modern designs and nanomaterial integration. This review explored the development of modern ISO by describing state-of-the-art strategies to improve their sensitivity, selectivity, and real-time monitoring capacity. The review reported the traditional membrane based-optodes, and investigated the latest research, current design principles, and the use of essential components, such as ionophores, indicator dyes, polymer membranes, and nanomaterials, in ISO fabrication. Special attention was given to nanomaterials (e.g., quantum dots, polymer dots, nanospheres, nanorods and nanocapsules) and particularly on how rare earth elements can further enhance their potential. It also described innovative ISO designs, including wearable optodes, smartphone-based optodes, and disposable paper-based optodes. As the pursuit of highly sensitive, selective, and adaptable ion sensing devices continues, this summary of the current knowledge sets the stage for upcoming innovations and applications in different domains (pharmaceutical formulations, medical diagnosis, environmental monitoring, and industrial applications).

Ionophore-modified polyaniline-based optode for the determination of hydrogen sulfite levels in beverages, wastewater, and soil

Sulfite is a very important species, affecting human health, plant and animal life, and environmental sustainability. In this study, for the first time, an ionophore-based ion-selective optode was constructed for hydrogen sulfite determination in beverages, such as Birell® and Sprite®, water, and soil samples; instead of normal pH-chromoionophores, polyaniline film was precipitated on a glass slide and used for the transduction of the sensation mechanism. The ionophore-modified polyaniline-based optode incorporated thiourea derivative as an ionophore and tridodecyl methyl ammonium chloride as an ion-exchanger. The optode film was prepared in situ with a modified chemical polymerization method, and it was characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD); also, FTIR spectroscopy was performed for the film before and after interaction with hydrogen sulfite for mechanism elucidation. The optode was applied in the hydrogen sulfite concentration range of 10-1 to 10-5 M with a low detection limit of 8.0 × 10-6 M and minimum interference of other interfering species, such as salicylate, iodide, and sulphide. The response mechanism was due to the ion-exchange of hydrogen sulfite with the anion exchanger, followed by the molecular recognition between thiourea ionophore and hydrogen sulfite, with concomitant redox reaction via the protonation of the polyaniline that causes a decrease in absorbance at 685 nm. The optode was applied successfully for the determination of hydrogen sulfite in real beverages, Birell® and Sprite® without any pretreatment steps. Also, it was applied successfully for the environmental monitoring of hydrogen sulfite in real wastewater and soil samples.

Biodegradable and Sustainable Synthetic Antibodies-A Perspective

Molecular imprinting technology has been around for almost a century, and we have witnessed dramatic advancements in the overall design and production of molecularly imprinted polymers (MIPs), particularly in terms of possible formats of the final products when it comes to truly resembling antibody substitutes, i.e., MIP nanoparticles (MIP NPs). Nonetheless, the overall technology appears to struggle to keep up with the current global sustainability efforts, as recently elucidated in the latest comprehensive reviews, which introduced the "GREENIFICATION" concept. In this review, we will try to elucidate if these advancements in MIP nanotechnology have indeed resulted in a sustainability amelioration. We will do so by discussing the general production and purification strategies for MIP NPs, specifically from a sustainability and biodegradation perspective, also considering the final intended application and ultimate waste management.

Non-Enzymatic Phenylboronic Acid-Based Optode Membrane for Glucose Monitoring in Serums of Diabetic Patients and in the Culture Medium of Human Embryos

Monitoring glucose levels is important not only for diabetics, but also for tracking embryonic development in human embryo culture media. In this study, an optochemical sensor (glucose-selective polymer membrane) was fabricated for the determination of glucose in serum from diabetic patients and the culture media of human embryos. The optode membranes were formulated using polyvinyl chloride (PVC) as the polymer matrix and 4',5'-dibromofluorescein octadecyl ester (ETH 7075) as the chromoionophore. The sensitivity of the optode membranes was optimized using two different plasticizers (tricresyl phosphate-TCP and nitrophenyloctyl ether-NOPE) and three ionophores (nitrophenylboronic acid-NPBA, trifluorophenyboronic acid-TFPBA, 4'-nitrobenzo-15-crown-5) and tested for glucose detection. The best optode membrane was formulated from 49.5% PVC, 49.5% TCP, 1% NPBA, and 1% ETH 7075. It showed a linear dynamic range of 10^-3 M to 10^-1 M, with a detection limit of 9 × 10^-4 M and a response time of 2 min. The detection mechanism involves H-bonding between NPBA and glucose, which was confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). The reaction also involves the formation of boronate esters in basic media with deprotonation of the chromoionophore (ETH 7075), leading to a decrease in UV-Vis absorbance at λmax = 530 nm. The membrane optode was used for glucose determination in synthetic culture medium, commercial embryo culture medium (GLOBAL^® TOTAL^® W/HEPES), and serum from normal and diabetic patients, showing good accuracy and precision of the optode.