A simple sonochemical assisted synthesis of NiMoO4/chitosan nanocomposite for electrochemical sensing of amlodipine in pharmaceutical and serum samples

Chitosan/platinum nanocubes/Mn(TPDCA)2-modified glassy carbon electrodes for the electrochemical quantification of amlodipine in unprocessed plasma samples

A novel electrochemical probe is developed to detect amlodipine (AMD) in unprocessed plasma samples. The fabrication process involves the synthesis of platinum nanocubes (Pt NCs) and Mn(TPDCA)2 complexes, which are then immobilized them onto the glassy carbon electrode (GCE) surface. The developed electrochemical probe demonstrates exceptional detection performance, with a wide dynamic range, outstanding selectivity, and commendable reproducibility. The linear range and lower limit of detection of the developed method are 53 nM-3.5 µM and 53 nM, respectively. Electrochemical experiments have been conducted to study the kinetics of electrooxidation on the modified electrode, revealing that the process is diffusion-controlled. Furthermore, method validation studies are performed to assess the accuracy, precision, and selectivity of the sensor, demonstrating excellent performance in all these aspects. Consequently, it can be concluded that the sensor is highly suitable for practical applications in drug analysis.

Binder-free and efficient voltammetric sensor based on Zn-Ca2CuO3 nanoparticles for simultaneous determination of amlodipine, acetaminophen, and ascorbic acid in hypertension patients

Amlodipine (AM) is a long active calcium channel blocker used to relax blood vessels by preventing calcium ion transport into the vascular walls and its supporting molecules acetaminophen (AP) and ascorbic acid (AA) are recommended for hypertension control and prevention. Considering their therapeutic importance and potential side effects due to over dosage, we have fabricated a sensor for individual and simultaneous determination of AA, AP, and AM in pharmaceuticals and human urine using novel Zn-doped Ca2CuO3 nanoparticles modified glassy carbon electrode (GCE). Optimally doped Ca2CuO3 (2.5 wt% Zn at Cu site) enhanced the detection of target molecules over much wider concentration ranges of 50 to 3130 µM for AA, 0.25 to 417 µM for AP, and 0.8 to 354 µM for AM with the corresponding lowest detection limits of 14 µM, 0.05 µM, and 0.07 µM, respectively. Furthermore, the Zn-Ca2CuO3/GCE exhibited excellent selectivity and high sensitivity even in the presence of several potential interfering agents. The usefulness of the developed electrode was tested using an amlodipine besylate tablet and urine samples of seven hypertension patients under medication. The results confirmed the presence of a significant amount of AP and AM in six patients' urine samples indicating that the personalized medication is essential and the quantum of medication need to be fixed by knowing the excess medicines excreted through urine. Thus, the Zn-Ca2CuO3/GCE with a high recovery percentage and good sensitivity shall be useful in the pharmaceutical and biomedical sectors.

Nanosensors in the detection of antihypertension drugs, a golden step for medication adherence monitoring

Hypertension is associated with structural and functional changes in blood vessels with increased arteriosclerosis, vascular inflammation, and endothelial dysfunction. Decreased adherence (compliance) to antihypertensive medications contributes significantly to morbidity and mortality in hypertensive patients. Antihypertensive drugs (AHTDs) and lifestyle changes are the main cornerstones for treating hypertension. Several approaches have been described in the literature for determining AHTDs based on different analytical techniques. Amongst biosensors are one of the most attractive tools due to their inherent advantages. Biosensors are used for the detection of wide range of biomarkers as well as different drugs in past two decades. The main focus of the present study is to review the latest biosensors developed for the detection of AHTDs. Readers of the present study will be able to familiarize themselves with biosensors as advanced and modern diagnostic tools while reviewing the most widely used AHTDs. In the present study, the routine methods are first reviewed and while examining their advantages and disadvantages, biosensors have been introduced as ideal alternative tools.

Study of Ni/Y2O3/Polylactic Acid Composite

This study demonstrates the successful synthesis of Ni/Y₂O₃ nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray pyrolysis technique. They were collected in a water suspension with polyvinylpyrrolidone (PVP) as the stabiliser. The presence of the Y₂O₃ core and Ni shell was confirmed with transmission electron microscopy (TEM) and with electron diffraction. The TEM observations revealed the formation of round particles with an average diameter of 466 nm, while the lattice parameter on the Ni particle's surface was measured to be 0.343 nm. The Ni/Y₂O₃ nanocomposite particle suspensions were lyophilized, to obtain a dried material that was suitable for embedding into a polylactic acid (PLA) matrix. The resulting PLA/Ni/Y₂O₃ composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/Y₂O₃ showed a slight average decrease (8.55%) in flexural strength and a small decrease from 3.7 to 3.3% strain at the break, when compared to the base PLA. These findings demonstrate the potential for utilising Ni/Y₂O₃ nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields.

Development of a New Route for the Immobilization of Unmodified Single-Stranded DNA on Chitosan Beads and Detection of Released Guanine after Hydrolysis

In this work, chitosan beads were used as a cost-effective platform for the covalent immobilization of unmodified single-stranded DNA, using glutaraldehyde as a cross-linking agent. The immobilized DNA capture probe was hybridized in the presence of miRNA-222 as a complementary sequence. The target was evaluated based on the electrochemical response of the released guanine, using hydrochloride acid as a hydrolysis agent. Differential pulse voltammetry technique and screen-printed electrodes modified with COOH-functionalized carbon black were used to monitor the released guanine response before and after hybridization. The functionalized carbon black provided an important signal amplification of guanine compared to the other studied nanomaterials. Under optimal conditions (6 M HCl at 65 °C for 90 min), an electrochemical-based label-free genosensor assay exhibited a linear range between 1 nM and 1 µM of miRNA-222, with a detection limit of 0.2 nM of miRNA-222. The developed sensor was successfully used to quantify miRNA-222 in a human serum sample.

Ruthenium and Nickel Molybdate-Decorated 2D Porous Graphitic Carbon Nitrides for Highly Sensitive Cardiac Troponin Biosensor

Two-dimensional (2D) layered materials functionalized with monometallic or bimetallic dopants are excellent materials to fabricate clinically useful biosensors. Herein, we report the synthesis of ruthenium nanoparticles (RuNPs) and nickel molybdate nanorods (NiMoO₄ NRs) functionalized porous graphitic carbon nitrides (PCN) for the fabrication of sensitive and selective biosensors for cardiac troponin I (cTn-I). A wet chemical synthesis route was designed to synthesize PCN-RuNPs and PCN-NiMoO₄ NRs. Morphological, elemental, spectroscopic, and electrochemical investigations confirmed the successful formation of these materials. PCN-RuNPs and PCN-NiMoO₄ NRs interfaces showed significantly enhanced electrochemically active surface areas, abundant sites for immobilizing bioreceptors, porosity, and excellent aptamer capturing capacity. Both PCN-RuNPs and PCN-NiMoO₄ NRs materials were used to develop cTn-I sensitive biosensors, which showed a working range of 0.1–10,000 ng/mL and LODs of 70.0 pg/mL and 50.0 pg/mL, respectively. In addition, the biosensors were highly selective and practically applicable. The functionalized 2D PCN materials are thus potential candidates to develop biosensors for detecting acute myocardial infractions.

Polymer based nanocomposites: A strategic tool for detection of toxic pollutants in environmental matrices

A large fraction of population is suffering from waterborne diseases due to the contaminated drinking water. Both anthropogenic and natural sources are responsible for water contamination. Revolution in industrial and agriculture sectors along with a huge increase in human population has brought more amount of wastes like heavy metals, pesticides and antibiotics. These toxins are very harmful for human health, therefore, it is necessary to sense their presence in environment. Conventional strategies face various problems in detection and quantification of these pollutants such as expensive equipment and requirement of high maintenance with limited portability. Recently, nanostructured devices have been developed to detect environmental pollutants. Polymeric nanocomposites have been found robust, cost effective, highly efficient and accurate for sensing various environmental pollutants and this is due to their porous framework, multi-functionalities, redox properties, great conductivity, catalytic features, facile operation at room temperature and large surface area. Synergistic effects between polymeric matrix and nanomaterials are responsible for improved sensing features and environmental adaptability. This review focuses on the recent advancement in polymeric nanocomposites for sensing heavy metals, pesticides and antibiotics. The advantages, disadvantages, operating conditions and future perspectives of polymeric nanocomposites for sensing toxic pollutants have also been discussed.

Pharmaceutical and drug delivery applications of chitosan biopolymer and its modified nanocomposite: A review

Due to their improved structural and functional properties as well as biocompatibility, biodegradability, and nontoxicity, chitosan and its nanoparticles are currently grasping the interest of researchers. Although numerous attempts have been made to apply chitosan and its derivatives to biological applications, few have reported in achieving its pharmacological and drug delivery. The goal of the current work is to provide a summary of the chitosan biopolymer's physical, chemical, and biological properties as well as its synthesis of nanoparticles and characterization of its modified nanocomposites. The drug delivery method and pharmaceutical applications of chitosan biopolymer and its modified nanocomposites are examined in further detail in this research. We will introduce also about the most current publications in this field of study as well as its recent expansion.

Intrinsic Lability of NiMoO4 to Excel the Oxygen Evolution Reaction

Nickel-based bimetallic oxides such as NiMoO₄ and NiWO₄, when deposited on the electrode substrate, show remarkable activity toward the electrocatalytic oxygen evolution reaction (OER). The stability of such nanostructures is nevertheless speculative, and catalytically active species have been less explored. Herein, NiMoO₄ nanorods and NiWO₄ nanoparticles are prepared via a solvothermal route and deposited on nickel foam (NF) (NiMoO₄/NF and NiWO₄/NF). After ensuring the chemical and structural integrity of the catalysts on electrodes, an OER study has been performed in the alkaline medium. After a few cyclic voltammetry (CV) cycles within the potential window of 1.0-1.9 V (vs reversible hydrogen electrode (RHE)), ex situ Raman analysis of the electrodes infers the formation of NiO(OH)_ED (ED: electrochemically derived) from NiMoO₄ precatalyst, while NiWO₄ remains stable. A controlled study, stirring of NiMoO₄/NF in 1 M KOH without applied potential, confirms that NiMoO₄ hydrolyzes to the isolable NiO, which under a potential bias converts into NiO(OH)_ED. Perhaps the more ionic character of the Ni-O-Mo bond in the NiMoO₄ compared to the Ni-O-W bond in NiWO₄ causes the transformation of NiMoO₄ into NiO(OH)_ED. A comparison of the OER performance of electrochemically derived NiO(OH)_ED, NiWO₄, ex-situ-prepared Ni(OH)₂, and NiO(OH) confirmed that in-situ-prepared NiO(OH)_ED remained superior with a substantial potential of 238 (±6) mV at 20 mA cm^-2. The notable electrochemical performance of NiO(OH)_ED can be attributed to its low Tafel slope value (26 mV dec^-1), high double-layer capacitance (C_dl, 1.21 mF cm^-2), and a low charge-transfer resistance (R_ct, 1.76 Ω). The NiO(OH)_ED/NF can further be fabricated as a durable OER anode to deliver a high current density of 25-100 mA cm^-2. Post-characterization of the anode proves the structural integrity of NiO(OH)_ED even after 12 h of chronoamperometry at 1.595 V (vs reversible hydrogen electrode (RHE)). The NiO(OH)_ED/NF can be a compatible anode to construct an overall water splitting (OWS) electrolyzer that can operate at a cell potential of 1.64 V to reach a current density of 10 mA cm^-2. Similar to that on NF, NiMoO₄ deposited on iron foam (IF) and carbon cloth (CC) also electrochemically converts into NiO(OH) to perform a similar OER activity. This work understandably demonstrates monoclinic NiMoO₄ to be an inherently unstable electro(pre)catalyst, and its structural evolution to polycrystalline NiO(OH)_ED succeeding the NiO phase is intrinsic to its superior activity.

Electrochemical sensing system for the analysis of emerging contaminants in aquatic environment: A review

This survey distinguishes understudied spaces of arising impurity research in wastewaters and the habitat, and suggests bearing for future checking. Thinking about the impeding effect of toxins on human wellbeing and biological system, their discovery in various media including water is fundamental. This review sums up and assesses the latest advances in the electrochemical detecting of emerging contaminants (ECs). This survey is expected to add to the advancement in electrochemical applications towards the ECs. Different electrochemical insightful procedures like Amperometry, Voltammetry has been examined in this overview. The improvement of cutting edge nanomaterial-based electrochemical sensors and biosensors for the discovery of drug compounds has accumulated monstrous consideration because of their benefits, like high affectability and selectivity, continuous observing, and convenience has been reviewed in this survey. This survey likewise features the diverse electrochemical treatment procedures accessible for the removal of ECs.

Marine Biological Macromolecules as Matrix Material for Biosensor fabrication

The Ocean covers two-third of our planet and has great biological heterogeneity. Marine organisms like algae, vertebrates, invertebrates, and microbes are known to provide many natural products with biological activities as well as potent sources of biomaterials for therapeutic, biomedical, biosensors, and climate stabilization. Over the years, the field of biosensors have gained huge attention due to their extraordinary ability to provide early disease diagnosis, rapid detection of various molecules and substances along with long term monitoring. This review aims to focus on the properties and employment of various biomaterials (Carbohydrate polymers, proteins, polyacids etc) of marine origin such as Alginate, Chitin, Chitosan, Fucoidan, Carrageenan, Chondroitin Sulfate (CS), Hyaluronic acid (HA), Collagen, marine pigments, marine nanoparticles, Hydroxyapatite (HAp), Biosilica, lectins, and marine whole cell in the design and development of biosensors. Further, this review also covers the source of such marine biomaterials and their promising evolution in the fabrication of biosensors that are potent to be employed in the biomedical, environmental science and agricultural sciences domains. The use of such fabricated biosensors harness the system with excellent specificity, selectivity, biocompatibility, thermally stable and minimal cost advantages. This article is protected by copyright. All rights reserved.