ABSTRACT
The construction of novel electrocatalysts for efficient and economic electrochemical sensors is continuously a significant conceptual barrier for the point-of-care technology. Binary metal oxides with heterostructures have gained plenty of attention due to their promising physicochemical properties. Herein, we develop a rapid and sensitive electrochemical probe for the detection of flufenamic acid (FFA) by using a zinc manganate (ZnMnO)-modified electrode. The formation of ZnMnO was confirmed by various analytical techniques, such as X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy and elemental mapping. The ZnMnO-based electrocatalyst, which was used for the electrochemical detection of FFA, shows better performance than the previously reported electrode materials. The ZnMnO assay shows a linear quantitative range from 0.05 to 116 µM with a limit of detection of 0.003 µM and sensitivity of 0.385 µA µM-1 cm-2. Its good electrochemical performance can be ascribed to the large surface area, rapid charge mass transfer, copious active sites, and high carrier mobility. The electrochemical study displays that the fabricated ZnMnO-based sensor has the potential to be applied in the clinical analysis. This work constructs an advanced functional electrode material with a microscale architecture for the point-of-care technology.
ABSTRACT
We report the rational design of nanocomposite with zirconium phosphate encapsulated on graphene oxide (ZrP/GO) for the highly sensitive and selective analysis of fenitrothion (FT). The characteristics of ZrP/GO nanocomposite are systematically analyzed by various in-depth electron microscopic, spectroscopic and analytical techniques. The ZrP/GO nanocomposite modified electrodes show better electrochemical response towards FT than other electrodes. The improved electrochemical activity of nanocomposite is attributed to large surface area, high conductivity, numerous active surface sites, GO nanosheets served as the conductivity matrix while preventing ZrP from agglomeration and the synergistic effect of ZrP and GO. Benefitting from the unique features, our fabricated sensor exhibits the superior performance in terms of wide working range (0.008-26 µM), appropriate peak potential (-0.61 V), low limit of detection (0.001 µM), high sensitivity (6 µA µM-1 cm-2) with the regression coefficient of 0.999. Additionally, the electrochemical sensor also displays good selectivity, excellent stability (99.6%), reproducibility (4.9%) and reusability (6.1%). The practical applicability of ZrP/GO sensor is shown by performing the detection of FT in water samples. These results clearly suggest that the ZrP/GO nanocomposite is an efficient electrode material for the future real-time environmental monitoring of FT.
ABSTRACT
Aquatic contamination from the accumulation of pharmaceuticals has induced severe toxicological impact to the ecological environment, especially from non-steroidal anti-inflammatory drugs (NSAIDs). Real-time monitoring of flutamide, which is a class of NSAIDs, is very significant in environmental protection. In this work, we have synthesized the hexagonal-h boron nitride decorated on bismuth oxide (Bi2O3/h-BN) based nanocomposite for the effective electrochemical detection of flutamide (FTM). The structural and morphological information of the heterostructured Bi2O3/h-BN nanocomposite was analyzed by using a sequence of characterization methods. Voltammetric techniques were used to evaluate the analytical performance of the Bi2O3/h-BN modified screen-printed carbon electrode (SPCE) for the FTM detection. The Bi2O3/h-BN modified SPCE displays a synergetic catalytic effect for the reduction of FTM due to large surface area, numerous active sites, fast charge transfer and abundant defects. The proposed electrochemical sensing platform demonstrates high selectivity, low detection limit (9.0 nM), good linear ranges (0.04-87 µM) and short response time for the detection of FTM. The feasibility of the electrochemical sensor has been proved by the successful application to determine FTM in environmental samples.
Subject(s)
Bismuth/chemistry , Boron Compounds/chemistry , Flutamide/chemistry , Nanocomposites/chemistry , Carbon/chemistry , Catalysis , Electrochemical Techniques/methods , ElectrodesABSTRACT
Rapid-monitoring of drugs has attracted tremendous consideration owing to robust global demand for cost-effective and high effectiveness. Binary metal oxides with various morphology have been reported as electrodes for electrochemical sensor to fulfilling the clinical and enviromental requirements. In this study, strontium tungstate (SrWO4) nanoflakes have been successfully prepared via the facile sonochemical method for the first time. The characteristics of as-prepared SrWO4 are systematically measured by various analytical and spectroscopic methods. The SrWO4 nanoflakes are utilized to modify the electrochemical electrode for the sulfadiazine (SDZ) determination. The SrWO4 modified electrode possesses excellent electrocatalytic activity and high recognition capability for the electrochemical detection of SDZ. Impressively, the as-fabricated SrWO4 modified electrode attainted lowest oxidation peak at +0.93 V (vs Ag/AgCl2) with the limit of detection of 0.009 µM, the sensitivity of 0.123 µA µM-1 cm2 and linear detection range of 0.05-235 µM. The enhanced performance of proposed SrWO4-based sensors could be attributed to the catalytic effect, large surface area, good electrical conductivity and physicochemical nature. Notably, the electrocatalytic performances of the SDZ sensors are good as compared to the previous literature, indicating the significance of the newly designed SrWO4 modified electrode. The real-sample diagnosis by the SDZ detection in environmental sample demonstrates the proposed SrWO4-based sensors with good recovery range.
