Evaluation of ZnO nanoparticle ionic liquid composite as a voltammetric sensing of isoprenaline in the presence of aspirin for liquid phase determination

Study of the molecular interaction of a phosphonium-based ionic liquid within myo-inositol and non-steroidal anti-inflammatory drugs

Ionic liquids (ILs) can be used as carriers and solubilizers as well as for increasing the effectiveness of drugs. In the present investigation, the micellar properties of phosphonium-based ionic liquids (PILs) such as trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate ([P666(14)][THPP]) and the effect of carbocyclic sugar-based myo-inositol (MI) and non-steroidal anti-inflammatory drugs (NSAIDs), i.e. ibuprofen (IBU) or aspirin (ASP), on the PIL micellar system were studied using surface tension, conductivity, colorimetry, viscometry, FTIR, and dynamic light scattering (DLS) at a temperature of 299 ± 0.5 K. The critical micelle concentrations (CMCs), particle size, zeta potential, and various interfacial parameters were also included i.e., efficiency of adsorption (pC20), surface tension at CMC (γCMC), minimum surface area per molecule (Amin), surface pressure at CMC (πCMC), maximum surface excess concentration (Γmax), and various thermodynamic parameters, such as standard Gibbs free energy of adsorption , standard Gibbs free energy of micellization per alkyl tail , standard Gibbs free energy of the air-water interface (ΔG(s)min), standard Gibbs free energy of transfer , and standard Gibbs free energy of micellization . The adsorption and micellization characteristics became more spontaneous, as shown by the more negative values of and . Viscosity-based rheological properties were calculated for various PIL + MI and PIL + MI + NSAID systems. According to the DLS data, the PIL (Z = 316.4 nm) micellar system generates substantially bigger micelles in an aqueous solution of MI + ASP (Z = 801.7 nm) than in MI + IBU (Z = 674.7 nm). FTIR spectroscopy revealed the interactions of PIL with MI + ASP and MI + IBU, where it was observed that MI + IBU shows good agreement with the PIL system compared to MI + ASP. The current research will have effects on pharmaceutical sciences, molecular biology, and drug delivery.

Ionic liquids on oxide surfaces

Ionic liquids (ILs) supported on oxide surfaces are being investigated for numerous applications including catalysis, batteries, capacitors, transistors, lubricants, solar cells, corrosion inhibitors, nanoparticle synthesis and biomedical applications. The study of ILs with oxide surfaces presents challenges both experimentally and computationally. The interaction between ILs and oxide surfaces can be rather complex, with defects in the oxide surface playing a key role in the adsorption behaviour and resulting electronic properties. The choice of the cation/anion pair is also important and can influence molecular ordering and electronic properties at the interface. These controllable interfacial behaviours make ionic liquid/oxide systems desirable for a number of different technological applications as well as being utilised for nanoparticle synthesis. This topical review aims to bring together recent experimental and theoretical work on the interaction of ILs with oxide surfaces, including TiO₂, ZnO, Al₂O₃, SnO₂and transition metal oxides. It focusses on the behaviour of ILs at model single crystal surfaces, the interaction between ILs and nanoparticulate oxides, and their performance in prototype devices.

Properties and Recent Advantages of N,N’-dialkylimidazolium-ion Liquids Application in Electrochemistry

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N,Nʹ-dialkylimidazolium-ion liquids is one of the important ionic liquids with a wide range of application as conductive electrolyte and in electrochemistry. The modified electrodes create a new view in fabrication of electroanalytical sensors. Many modifiers have beeen suggested for modification of electroanalytical sensor since many years ago. Over these years, ionic liquids and especially room temperature ionic liquids have attracted more attention due to their wide range of electrochemical windows and high electrical conductivity. N,Nʹ-dialkylimidazolium-ion liquids are one of the main important ionic liquids suggested for modification of bare electrodes and especially carbon paste electrodes. Although many review articles have reported onthe use of ionic liquids in electrochemical sensors, no review article has been specifically introduced so far on the review of the advantages of N,Nʹ-dialkylimidazolium ionic liquid. Therefore, in this review paper we focused on the introduction of recent advantages of N,Nʹ-dialkyl imidazolium ionic liquid in electrochemistry.

Nano optical and electrochemical sensors and biosensors for detection of narrow therapeutic index drugs

For the first time, a comprehensive review is presented on the quantitative determination of narrow therapeutic index drugs (NTIDs) by nano optical and electrochemical sensors and biosensors. NTIDs have a narrow index between their effective doses and those at which they produce adverse toxic effects. Therefore, accurate determination of these drugs is very important for clinicians to provide a clear judgment about drug therapy for patients. Routine analytical techniques have limitations such as being expensive, laborious, and time-consuming, and need a skilled user and therefore  the nano/(bio)sensing technology leads to high interest.

Bifunctional PVA/ZnO/AgI/Chlorophyll Nanocomposite Film: Enhanced Photocatalytic Activity for Degradation of Pollutants and Antimicrobial Property under Visible-Light Irradiation

Here, poly(vinyl alcohol) (PVA) with numerous hydroxyl groups has been applied as a suitable substrate for efficient formation of zinc oxide (ZnO) nanoparticles with a flower shape (confirmed by electron-scanning microscopy), silver iodide (AgI) nanoparticles, and chlorophyll (Chl), as a natural-based photocatalyst (PVA/ZnO/AgI/Chl). First, an efficient preparation route for the PVA/ZnO/AgI/Chl nanophotocatalyst is presented starting from the extraction of Chl from fresh spinach. Then, the catalytic role of the prepared composite is precisely investigated in degradation of methylene blue (MB). The effects of visible-light irradiation, different contact times, and the employed ingredients on the architecture of the PVA/ZnO/AgI/Chl are screened in the degradation process of MB. It is demonstrated that the best result (MB removal efficiency ca. 95.5%) is achieved by applying the visible-light irradiation using a LED lamp (70 W, λ = 425 nm) for a 60 min duration. Moreover, the photocatalytic performance of PVA/ZnO/AgI/Chl has been further confirmed by degradation of Congo red (CR) (ca. 92%, in 150 min) and 4-chlorophenol (4-CP) (88%, in 270 min), as well. As another function of the prepared PVA/ZnO/AgI/Chl composite, a substantial antibacterial property against human bacterial pathogens such as Staphylococcus aureus and Escherichia coli as Gram-positive and Gram-negative bacteria has been noticed, studied by agar diffusion cup plate and colony methods. The zones of inhibition have been evaluated ca. 20 and 12 mm for the S. aureus and E. coli cell lines, respectively. Finally, a great synergy between the prepared composite and the visible light has been observed through the examination of the live bacteria: 99.6% for S. aureus and 99.8% for E. coli in the presence of visible light, after the subjection of PVA/ZnO/AgI/Chl particles to the bacteria, verified by the colony counter method.

Recent advances in ZnO nanostructure-based electrochemical sensors and biosensors

Nanostructured metal oxides, such as zinc oxide (ZnO), are considered as excellent materials for the fabrication of highly sensitive and selective electrochemical sensors and biosensors due to their good properties, including a high specific surface area, high catalytic efficiency, strong adsorption ability, high isoelectric point (IEP, 9.5), wide band gap (3.2 eV), biocompatibility and high electron communication features. Thus, ZnO nanostructures are widely used to fabricate efficient electrochemical sensors and biosensors for the detection of various analytes. In this review, we have discussed the synthesis of ZnO nanostructures and the advances in various ZnO nanostructure-based electrochemical sensors and biosensors for medical diagnosis, pharmaceutical analysis, food safety, and environmental pollution monitoring.

Gold-Platinum Core-Shell Nanoparticles with Thiolated Polyaniline and Multi-Walled Carbon Nanotubes for the Simultaneous Voltammetric Determination of Six Drug Molecules

In this proof-of-concept study, a novel nanocomposite of the thiolated polyaniline (tPANI), multi-walled carbon nanotubes (MWCNTs) and gold–platinum core-shell nanoparticles (Au@Pt) (tPANI-Au@Pt-MWCNT) was synthesized and utilized to modify a glassy carbon electrode (GCE) for simultaneous voltammetric determination of six over-the-counter (OTC) drug molecules: ascorbic acid (AA), levodopa (LD), acetaminophen (AC), diclofenac (DI), acetylsalicylic acid (AS) and caffeine (CA). The nanocomposite (tPANI-Au@Pt-MWCNT) was characterized with transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Using the sensor (GCE-tPANI-Au@Pt-MWCNT) in connection with differential pulse voltammetry (DPV), the calibration plots were determined to be linear up to 570.0, 60.0, 60.0, 115.0, 375.0 and 520.0 µM with limit of detection (LOD) of 1.5, 0.25, 0.15, 0.2, 2.0, and 5.0 µM for AA, LD, AC, DI, AS and CA, respectively. The nanocomposite-modified sensor was successfully used for the determination of these redox-active compounds in commercially available OTC products such as energy drinks, cream and tablets with good recovery yields ranging from 95.48 ± 0.53 to 104.1 ± 1.63%. We envisage that the electrochemical sensor provides a promising platform for future applications towards the detection of redox-active drug molecules in pharmaceutical quality control studies and forensic investigations.

Electrochemical sensors for β-adrenoceptor agonist isoprenaline analysis in human urine and serum samples using manganese cobalt oxide-modified glassy carbon electrode

Schematic illustration for the synthesis of the MCO nanosphere and modification with GCE towards the electrochemical determination of isoprenaline.

An electrochemical sensor based on chitosan capped with gold nanoparticles combined with a voltammetric electronic tongue for quantitative aspirin detection in human physiological fluids and tablets

Inflammatory diseases increase has recently sparked the research interest for drugs diagnostic tools development. At therapeutic doses, acetylsalicylic acid (ASA or aspirin) is widely used for these diseases' treatment. ASA overdoses can however give rise to adverse side effects including ulcers, gastric damage. Hence, development of simple, portable and sensitive methods for ASA detection is desirable. This paper reports aspirin analysis in urine, saliva and pharmaceutical tablet using an electrochemical sensor and a voltammetric electronic tongue (VE-Tongue). The electrochemical sensor was fabricated by self-assembling chitosan capped with gold nanoparticles (Cs + AuNPs) on a screen-printed carbon electrode (SPCE). It exhibits a logarithmic-linear relationship between its response and the ASA concentration in the range between 1 pg/mL and 1 μg/mL. A low detection limit (0.03 pg/mL), good selectivity against phenol and benzoic acid interference, and successful practical application were demonstrated. Qualitative analysis was performed using the VE-Tongue based unmodified metal electrodes combined with two chemometric approaches to classify urine samples spiked with different aspirin concentrations. Partial least squares (PLS) method provided prediction models obtained from the data of both devices with a regression correlation coefficient R² = 0.99. Correspondingly, the SPCE/(Cs + AuNPs) electrochemical sensor and VE-Tongue could be viable tools for biological analysis of drugs.

Carbon Paste Modified Electrode as Powerful Sensor Approach Determination of Food Contaminants, Drug Ingredients, and Environmental Pollutants: A Review

Background:

Application of electrochemical sensors for analysis of food, biological and water polluting compounds helps to speed up their analysis in the real samples. Electrochemical sensors with low cost, fast response and portable ability are a better choice compared to traditional methods for analysis of electro-active compounds such as HPLC. Therefore, in recent years, many analytical scientists have suggested this type of analytical method for analysis of food, biological compounds and water pollutants.

Objective:

Due to low cost, easy modification and low non-faradic current, the carbon paste electrode is a suitable choice as a working electrode in the electrochemical and especially voltammetric analysis. On the other hand, modification of carbon paste electrode can improve the quality of the sensor for the analysis of electroactive compounds at nanomolar level.

Application of novel Ni(II) complex and ZrO2 nanoparticle as mediators for electrocatalytic determination of N-acetylcysteine in drug samples

The electrooxidation of N-acetylcysteine (N-AC) was studied by a novel Ni(II) complex modified ZrO₂ nanoparticle carbon paste electrode [Ni(II)/ZrO₂/NPs/CPE] using voltammetric methods. The results showed that Ni(II)/ZrO₂/NPs/CPE had high electrocatalytic activity for the electrooxidation of N-AC in aqueous buffer solution (pH = 7.0). The electrocatalytic oxidation peak currents increase linearly with N-AC concentrations over the concentration ranges of 0.05-600μM using square wave voltammetric methods. The detection limit for N-AC was equal to 0.009μM. The catalytic reaction rate constant, k_h, was calculated (7.01 × 10² M^-1 s^-1) using the chronoamperometry method. Finally, Ni(II)/ZrO₂/NPs/CPE was also examined as an ultrasensitive electrochemical sensor for the determination of N-AC in real samples such as tablet and urine.

Xanthine sensor development based on ZnO–CNT, ZnO–CB, ZnO–GO and ZnO nanoparticles: an electrochemical approach

The wet-chemical method was used to prepare the various ZnO–CNT, ZnO–CB, ZnO–GO nanocomposites, and ZnO nanoparticles in higher pH medium, which were finally utilized with 5% nafion to produce a thin film of NCs/Nafion/GCE sensor that has a faster response towards selected xanthine with higher sensitivity, lower detection limit, and large linear dynamic range by electrochemical approach.

Fabrication of a new biosensor based on a Sn doped ceria nanoparticle modified glassy carbon paste electrode for the selective determination of the anticancer drug dacarbazine in pharmaceuticals

A new tin doped ceria nanoparticle modified glassy carbon paste electrode (Sn–CeO₂NPs/GCPE) was fabricated for the determination of the anticancer drug dacarbazine (DTIC).

Green synthesis of silver nanoparticles using onion extract and their application for the preparation of a modified electrode for determination of ascorbic acid

A high-quality method for one-pot biosynthesis of silver nanoparticles (AgNPs) using onion extracts as reductant and stabilizer is reported. The synthesized AgNPs were characterized by ultraviolet-visible spectroscopy (UV-Vis), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). UV-Vis spectroscopy results showed that the AgNP absorption band was located at a peak of 397 nm in aqueous solution. Both XRD and TEM results confirmed that the AgNPs were mainly spherical with average diameters of 6.0 nm by TEM and about 5.3-10.2 nm calculated using XRD data. The ability of AgNPs to reduce charge transfer resistance was also investigated using electrochemical impedance spectroscopy. Finally, the effect of synthesized NPs on ascorbic acid signal was investigated by square wave voltammetry. The peak current of square wave voltammograms of ascorbic acid increased linearly with its concentration in the range of 0.4-450.0μM. The detection limit for ascorbic acid was 0.1μM.