Samarium vanadate nanospheres integrated carbon nanofiber composite as an efficient electrocatalyst for antituberculosis drug detection in real samples

Ingenious fabrication of bamboo leaf-like ferric vanadate intertwined multi-walled carbon nanotubes nanocomposite as a sensitive sensor for determination of uric acid in fetal bovine serum

A novel nanocomposite material, ferric vanadate intertwined multi-walled carbon nanotubes (FeV/MWCNTs), has been designed which was drop-coated onto a glassy carbon electrode (GCE). The constructed sensor was used for the sensitive determination of uric acid (UA) in fetal bovine serum (FBS) and human serum (HS). A series of characterization and electrochemical tests showed that the ultrasound-assisted assembly of FeV with MWCNTs not only overcame the disadvantages of low conductivity and easy (unwanted) aggregation, but also avoided the decrease in effective surface area due to the severe aggregation of each individual raw material. The fabricated FeV/MWCNTs nanocomposites exhibited higher conductivity, larger effective surface area, and better electrocatalytic activity. In addition, under optimized conditions, the developed electrochemical sensor FeV/MWCNTs/GCE has a lower limit of detection (LOD, 0.05 µM; Ep = 0.268 V vs. Ag/AgCl) and wider linear range (0.20-100 µM), which can satisfy the criteria of trace UA detection. The results of UA determination in FBS (recovery = 95.5-103%; RSD ≤ 3.1%) and HS (recovery = 95.5-103%; RSD ≤ 4.3%) further validated the feasibility of FeV/MWCNTs-based electrochemical sensors for the determination of UA in biological fluids.

Fabrication of Praseodymium Vanadate Nanoparticles on Disposable Strip for Rapid and Real-Time Amperometric Sensing of Arsenic Drug Roxarsone

Nanomaterials have versatile properties owing to their high surface-to-volume ratio and can thus be used in a variety of applications. This work focused on applying a facile hydrothermal strategy to prepare praseodymium vanadate nanoparticles due to the importance of nanoparticles in today's society and the fact that their synthesis might be a challenging endeavor. The structural and morphological characterizations were carried out to confirm the influence of the optimizations on the reaction's outcomes, which revealed praseodymium vanadate (PrVO₄) with a tetragonal crystal system. In this regard, the proposed development of electrochemical sensors based on the PrVO₄ nanocatalyst for the real-time detection of arsenic drug roxarsone (RXS) is a primary concern. The detection was measured by amperometric (i-t) signals where PrVO₄/SPCE, as a new electrochemical sensing medium for RXS detection, increased the sensitivity of the sensor to about ∼2.5 folds compared to the previously reported ones. In the concentration range of 0.001-551.78 μM, the suggested PrVO₄/SPCE sensor has a high sensitivity for RXS, with a detection limit of 0.4 nM. Furthermore, the impact of several selected potential interferences, operational stability (2000 s), and reproducibility measurements have no discernible effect on RXS sensing, making it the ideal sensing device feasible for technical analysis. The real-time analysis reveals the excellent efficiency and reliability of the prosed sensor toward RXS detection with favorable recovery ranges between ±97.00-99.66% for chicken, egg, water, and urine samples.

Carbon Nanomaterials-Based Novel Hybrid Platforms for Electrochemical Sensor Applications in Drug Analysis

Nowadays, the rapid improvements in the medical and pharmaceutical fields increase the diversity and use of drugs. However, problems such as the use of multiple or combined drugs in the treatment of diseases and insensible use of over-the-counter drugs have caused concerns about the side-effect profiles and therapeutic ranges of drugs and environmental contamination and pollution problems due to pharmaceuticals waste. Therefore, the analysis of drugs in various media such as biological, pharmaceutical, and environmental samples is an important topic of discussion. Electrochemical methods are advantageous for sensor applications due to their easy application, low cost, versatility, high sensitivity, and environmentally-friendliness. Carbon nanomaterials such as diamond-like carbon thin films, carbon nanotubes, carbon nanofibers, graphene oxide, and nanodiamonds are used to enhance the performance of the electrochemical sensors with catalytic effects. To further improve this effect, it is aimed to create hybrid platforms by using different carbon nanomaterials together or with materials such as conductive polymers and ionic liquids. In this review, the most used carbon nanoforms will be evaluated in terms of electrochemical characterizations and physicochemical properties. Furthermore, the effect of hybrid platforms developed in the most recent studies on electrochemical sensors will be examined and evaluated in terms of drug analysis studies in the last five years.

Toward the Development of Disposable Electrodes Based on Holmium Orthovanadate/f-Boron Nitride: Impacts and Electrochemical Performances of Emerging Inorganic Contaminants

Rare-earth metal orthovanadates have great technological relevance in the family of rare-earth compounds owing to their excellent physical and chemical properties. A significant number of studies have been carried out on this class of compounds to exploit their electrochemical properties in virtue of variable oxidation states. But holmium vanadate (HoV) and its morphology selective synthesis have not been considered, which can have potential applications similar to the rest of the family. In this work, we propose the synthesis of superior architectures of HoV with a functionalized boron nitride (f-BN) nanocomposite. The synergistic effect between HoV and f-BN can have a positive effect on the physical characteristics of the nanocomposite, which can be explored for its electrochemical capacity. Here, HoV incorporated with f-BN is explored for the electrochemical detection of Hg²⁺ ions, which is known for its toxicity-induced environmental health hazards. The structural and compositional revelation reveals higher conductivity and faster electron transfer in the composite, which facilitates a wide working range (0.02-53.8 and 64.73-295.4 μM), low limit of detection (5 nM), higher sensitivity (66.6 μA μM^-1 cm^-2), good selectivity over 10-fold higher concentration of other interfering compounds compared to Hg²⁺ ion concentration, and good cycles stability (30 segments) toward Hg²⁺ ion detection. This also envisages the morphology selective synthesis and utilization of other rare-earth metals, whose electrochemical capacities are unexplored.