Ultrathin 2D graphitic carbon nitride nanosheets decorated with silver nanoparticles for electrochemical sensing of quercetin

A portable magnetic electrochemical sensor for highly efficient Pb(II) detection based on bimetal composites from Fe-on-Co-MOF

The practical, sensitive, and real-time detection of heavy metal ions is an essential and difficult problem. This study presents the design of a unique magnetic electrochemical detection system that can achieve real-time field detection. To enhance the electrochemical performance of the sensor, Fe2O3@C-800, Co/CoO@/C-600, and CoFe2O4@C-600 magnetic composites were synthesized using three MOFs precursors by the solvothermal method. And the morphology structure and electrochemical properties of as-prepared magnetic composites were researched by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), specific surface area and porosity analyzer (BET) and differential pulse voltammetry (DPV). The results shown that these composites improve conductivity and stability while preserving the MOFs basic frame structure. Compared with the monometallic MOFs-derived composites, the synergistic effect of the bimetallic composite CoFe2O4@C-600 can significantly enhance the electrochemical performance of the sensor. The linear range for the detection of lead ions was 0.001-60 μM, and the detection limit was 0.0043 μM with a sensitivity of 22.22 μA μM·cm-2 by differential pulse voltammetry. The sensor has good selectivity, stability, reproducibility and can be used for actual sample testing.

ZIF-67 based CoS2 self-assembled on graphitic carbon nitride microtubular for sensitive electrochemical detection of paraquat in fruits

Paraquat (PQ) is a widely used and harmful herbicide that must be detected in the environment. This study reports a novel composite (CoS2-GCN) prepared by assembling cobalt disulfide (CoS2) derived from metal-organic frameworks (MOFs) on graphitic carbon nitride (GCN). An electrochemical sensor (CoS2-GCN/ glassy carbon electrode (GCE)) was successfully prepared by modifying CoS2-GCN onto a GCE to sensitively detect PQ. Different concentrations of PQ were detected using square-wave voltammetry, and the CoS2-GCN/GCE electrochemical sensor showed remarkable response signals for PQ in the range of 20 - 1000 nM and 1 - 13 μM, with a detection limit of 4.13 nM (S/N = 3). The CoS2-GCN/GCE electrochemical sensor exhibited high stability, reproducibility, and immunity to interference, which were attributed to the synergistic effects of CoS2 and GCN. In addition, the CoS2-GCN/GCE electrochemical sensor showed high applicability for the analysis of fruit samples. Therefore, the proposed sensor has potential applications in PQ detection.

Insights in Electrochemical Determination of Quercetin in Peach Vinegar by the Hexagonal Platinum Nanocrystal

Peach vinegar is a popular condiment that is thought to have various health benefits. However, the low levels of quercetin and complex detection environment in peach vinegar make it difficult to detect using traditional methods. Electrochemical detection is a promising solution because it is sensitive, inexpensive, and provides real-time results. Herein, a hexagonal Pt nanocrystal was developed as an electrocatalyst for selective detection of quercetin in peach vinegar, and a comprehensive examination was given of the electrochemical characteristics of quercetin when applied to electrodes modified with platinum. The morphology and crystal properties of Pt nanocrystals were analyzed, and the Pt-modified electrode was found to exhibit strong electrocatalytic effects toward quercetin in peach vinegar with a high sensitivity of 58 μA μM-1. Furthermore, the investigation showcased exceptional specificity, consistency, sustained durability, and replicability of the Pt-modified electrode in identifying quercetin. The detection result of the Pt-modified electrode tested in three different peach vinegar samples demonstrated its practical utility in real-world applications. Overall, the findings of this study may have important implications for the development of more efficient and sensitive electrochemical sensors for the detection of quercetin and other analytes in vinegar.

Efficient photocatalytic reduction of p-nitrophenol under visible light irradiation based on Ag NPs loaded brown 2D g-C3N4 / g-C3N4 QDs nanocomposite

Recently, low-cost graphitic carbon nitride (g-C3N4) revealed high photocatalytic activities and provided solutions to environmental pollution. In this study, we synthesized brown mesoporous 2D g-C3N4 by calcination dicyandiamide with pluronic P123. This is followed by loading of Ag NPs on the prepared 2D g-C3N4 by photodeposition process. After that, a ternary composite 2% Ag/ 2D g-C3N4 / g-C3N4 QDs heterojunction photocatalyst has been successfully prepared. The prepared nanomaterials were comprehensively characterized by various analysis techniques such as XRD, UV-Vis., BET, XPS, SEM, TEM. This new system exhibited a large surface area with porous structure and a wide absorption of visible light. The results verified that Ag NPs decoration enhanced the charge separation of photo-generated carriers of g-C3N4 2D and g-C3N4 QDs, promote significant enhancement in the photocatalytic activity for reduction of p-nitrophenol with a rate constant (k) value of 0.49729 / min in 6 min. This rate is about two-fold higher than that observed for pure g-C3N4 2D and g-C3N4 QDs as well as shows an improvement compared to 2% Ag/ g-C3N4 2D and g-C3N4 2D/ g-C3N4 QDs. The results open the door to design highly efficient 2D/0D nanocomposite photocatalysts for a wide variety of environmental applications.

Electrochemistry of Flavonoids: A Comprehensive Review

Flavonoids represent a large group of aromatic amino acids that are extensively disseminated in plants. More than six thousand different flavonoids have been isolated and identified. They are important components of the human diet, presenting a broad spectrum of health benefits, including antibacterial, antiviral, antimicrobial, antineoplastic, anti-mutagenic, anti-inflammatory, anti-allergic, immunomodulatory, vasodilatory and cardioprotective properties. They are now considered indispensable compounds in the healthcare, food, pharmaceutical, cosmetic and biotechnology industries. All flavonoids are electroactive, and a relationship between their electron-transfer properties and radical-scavenging activity has been highlighted. This review seeks to provide a comprehensive overview concerning the electron-transfer reactions in flavonoids, from the point of view of their in-vitro antioxidant mode of action. Flavonoid redox behavior is related to the oxidation of the phenolic hydroxy groups present in their structures. The fundamental principles concerning the redox behavior of flavonoids will be described, and the phenol moiety oxidation pathways and the effect of substituents and experimental conditions on flavonoid electrochemical behavior will be discussed. The final sections will focus on the electroanalysis of flavonoids in natural products and their identification in highly complex matrixes, such as fruits, vegetables, beverages, food supplements, pharmaceutical compounds and human body fluids, relevant for food quality control, nutrition, and healthcare research.

A robust electrochemical sensor based on N,S-FeNi3/C for simultaneous detection of hydroquinone and arbutin in cosmetics

For practical analysis and simultaneous detection of arbutin (AR) and hydrochinone (HQ) in cosmetics, an electrochemical sensor has been designed based on nitrogen and sulfur co-doped Fe-Ni alloy (N,S-FeNi₃/C) nanoparticles. The N,S-FeNi₃/C has been prepared for the first time via hydrothermal synthesis and high-temperature carbonization. N,S-FeNi₃/C not only improves the charge transfer to the surface, but also provides rich active sites and fast ion diffusion rates owing to the iron and nickel bimetallic materials. In addition, the d-band structure of transition metals (nickel and iron) introduced by the N and S atoms exhibits an electronic structure similar to that of noble metal catalysts, thus enhancing electrocatalytic activity and increasing conductivity. Additionally, the double doping of S and N atoms significantly increases the active sites of carbon atoms; thus, N-S-FeNi3/C exhibits excellent electrochemical catalytic activity for the oxidation of AR and HQ. Further, the N,S-FeNi₃/C sensor is used for the simultaneous determination of HQ and AR by square-wave pulse voltammetry. Distinct oxidation peaks of HQ and AR are observed at potentials of +0.028 V and +0.352 V (vs. SCE). The electrical signal increases linearly in the HQ concentration ranges of 0.1-100 μM and 0.05-70 μM for the simultaneous determination of AR and HQ with a detection limit as low as 0.0476 and 0.0135 μM (S/N = 3), respectively. Thus, rapid and accurate detection of AR and HQ in spiked cosmetics is successfully achieved, with a recovery ranging from 96.4 to 104.2%, and the relative standard deviation is lower than 3.8-4.0%.

Emerging and Promising Multifunctional Nanomaterial for Textile Application Based on Graphitic Carbon Nitride Heterostructure Nanocomposites

Nanocomposites constructed with heterostructures of graphitic carbon nitride (g-C₃N₄), silver (Ag), and titanium dioxide (TiO₂) have emerged as promising nanomaterials for various environmental, energy, and clinical applications. In the field of textiles, Ag and TiO₂ are already recognized as essential nanomaterials for the chemical surface and bulk modification of various textile materials, but the application of composites with g-C₃N₄ as a green and visible-light-active photocatalyst has not yet been fully established. This review provides an overview of the construction of Ag/g-C₃N₄, TiO₂/g-C₃N₄, and Ag/TiO₂/g-C₃N₄ heterostructures; the mechanisms of their photocatalytic activity; and the application of photocatalytic textile platforms in the photochemical activation of organic synthesis, energy generation, and the removal of various organic pollutants from water. Future prospects for the functionalization of textiles using g-C₃N₄-containing heterostructures with Ag and TiO₂ are highlighted.

Development of robust multifunctional CrNiCo-P/GCN catalyst for oxygen evolution reaction, electrochemical sensing, and photodegradation of roxarsone

In this study, we designed a CrNiCo-P/GCN composite for use as a high-performance multifunctional catalyst for the oxygen evolution reaction (OER), electrochemical determination, and photodegradation of roxarsone (ROX). CrNiCo-P/GCN demonstrates favorable charge resistance and electrical conductance due to its intrinsic properties. It exhibits an admirable OER overpotential of 290 mV with a lower Tafel plot value of 125 mV dec^-1 in alkaline media and compared with the control samples. Furthermore, this composite also demonstrates high performance in electrochemical sensing of ROX over a wide concentration range of 1-413 μM with a lower limit of detection (LOD) of 31 nM in phosphate buffer. Moreover, this composite is a promising electrocatalyst for ROX sensors in practical analysis and also possesses excellent photodegradation of ROX under visible light irradiation.

Nanomaterials-based electrochemical sensors for the detection of natural antioxidants in food and biological samples: research progress

Antioxidants are healthy substances that are beneficial to the human body and exist mainly in natural and synthetic forms. Among many kinds of antioxidants, the natural antioxidants have great applications in many fields such as food chemistry, medical care, and clinical application. In recent years, many efforts have been made for the determination of natural antioxidants. Nano-electrochemical sensors combining electrochemistry and nanotechnology have been widely used in the determination of natural antioxidants due to their unique advantages. Therefore, a large number of nanomaterials such as metal oxide, carbon materials, and conducting polymer have attracted much attention in the field of electrochemical sensors due to their good catalytic effect and stable performance. This review mainly introduces the construction of electrochemical sensors based on different nanomaterials, such as metallic nanomaterials, metal oxide nanomaterials, carbon nanomaterials, metal-organic frameworks, polymer nanomaterials, and other nanocomposites, and their application to the detection of natural antioxidants, including ascorbic acid, phenolic acids, flavonoid, tryptophan, citric acid, and other natural antioxidants. In the end, the limitations of the existing nano-sensing technology, the latest development trend, and the application prospect for various natural antioxidant substances are summarized and analyzed. We expect that this review will be helpful to researchers engaged in electrochemical sensors.

A Comprehensive Review on the Electrochemical Sensing of Flavonoids

Flavonoids are bioactive polyphenolic compounds, widespread in the plant kingdom. Flavonoids possess broad-spectrum pharmacological effects due to their antioxidant, anti-tumor, anti-neoplastic, anti-mutagenic, anti-microbial, anti-inflammatory, anti-allergic, immunomodulatory, and vasodilatory properties. Care must be taken, since excessive consumption of flavonoids may have adverse effects. Therefore, proper identification, quantification and quality evaluations of flavonoids in edible samples are necessary. Electroanalytical approaches have gained much interest for the analysis of redox behavior and quantification of different flavonoids. Compared to various conventional methods, electrochemical techniques for the analysis of flavonoids offer advantages of high sensitivity, selectivity, low cost, simplicity, biocompatibility, easy on-site evaluation, high accuracy, reproducibility, wide linearity of detection, and low detection limits. This review article focuses on the developments in electrochemical sensing of different flavonoids with emphasis on electrode modification strategies to boost the electrocatalytic activity and analytical efficiency.

Silver nanomaterials: synthesis and (electro/photo) catalytic applications

In view of their unique characteristics and properties, silver nanomaterials (Ag NMs) have been used not only in the field of nanomedicine but also for diverse advanced catalytic technologies. In this comprehensive review, light is shed on general synthetic approaches encompassing chemical reduction, sonochemical, microwave, and thermal treatment among the preparative methods for the syntheses of Ag-based NMs and their catalytic applications. Additionally, some of the latest innovative approaches such as continuous flow integrated with MW and other benign approaches have been emphasized that ultimately pave the way for sustainability. Moreover, the potential applications of emerging Ag NMs, including sub nanomaterials and single atoms, in the field of liquid-phase catalysis, photocatalysis, and electrocatalysis as well as a positive role of Ag NMs in catalytic reactions are meticulously summarized. The scientific interest in the synthesis and applications of Ag NMs lies in the integrated benefits of their catalytic activity, selectivity, stability, and recovery. Therefore, the rise and journey of Ag NM-based catalysts will inspire a new generation of chemists to tailor and design robust catalysts that can effectively tackle major environmental challenges and help to replace noble metals in advanced catalytic applications. This overview concludes by providing future perspectives on the research into Ag NMs in the arena of electrocatalysis and photocatalysis.

Well-Designed Construction of Yttrium Orthovanadate Confined on Graphitic Carbon Nitride Sheets: Electrochemical Investigation of Dimetridazole

Antibiotics are the most important drugs for people and animals to fight bacterial illnesses. Overuse of antibiotics has had unintended consequences, such as antibiotic resistance and ecosystem eradication owing to toxic chemical discharge, which have a negative influence on the biome. Herein, we report the synthesis of a hollow ellipsoid-shaped yttrium vanadate/graphitic carbon nitride (YVO₄@CN) nanocomposite by a hydrothermal approach followed by a sonochemical method for the effective detection of dimetridazole (DMZ). The synergic and coupling effect between both the phases offer non-linear cumulative ramifications which can positively enhance the individual properties of the materials under consideration. This positive hybrid effect increases the conductivity, shortens the ion-diffusion pathway, enhances the electron/ion transportation, and provides more active sites and electron-conducting channels. The accurate optimization of the experimental conditions proposes good electrocatalytic activity for the YVO₄@CN catalyst, exhibiting a good response toward DMZ detection. It reveals an extensive linear concentration range (0.001-153.3 and 176.64-351.6 μM), a low detection limit (0.8 nM), higher sensitivity (4.98 μA μM^-1 cm^-2), appreciable selectivity, increased operational stability (2200 s), and good cycle stability (60 cycles). The electrochemical performance of YVO₄@CN indicates its practical application in real-time sample analysis of several families of nitroimidazole drugs.

Hybrid nanostructures of Pd-WO3 grown on graphitic carbon nitride for trace level electrochemical detection of paraoxon-ethyl

Well-defined crystal structures of Pd-doped WO₃ nanorods were assembled on graphitic carbon sheets (Pd-WO₃/g-C₃N₄) for ultrasensitive detection of paraoxon-ethyl (PEL) using an electrochemical method. The electrochemical behavior of PEL on the Pd-WO₃/g-C₃N₄ hybrid composite was investigated using cyclic voltammetry (CV) and amperometric techniques. The Pd-WO₃ crystallite was seen to modify the kinetics of g-C₃N₄, which improved the reduction/redox peak currents of PEL at the Pd-WO₃/g-C₃N₄ composite compared to those of the g-C₃N₄ and WO₃/g-C₃N₄-modified electrode. Moreover, the π-π interaction and hydrogen bond between the PEL and Pd-WO₃/g-C₃N₄ composite improved the charge-transfer properties. The Pd-WO₃/g-C₃N₄ hybrid composite was therefore able to obtain an enhanced sensitivity (3.70 ± 0.05 μA μM^-1 cm^-2) and low detection limit (0.03 nM; S/N = 3) with a wide range of linear concentrations (0.01-60 and 80-900.0 ± 5 μM) at applied potential of - 0.63 V (vs. Ag/AgCl). The detection of PEL in agricultural water and soil samples was successfully demonstrated with satisfactory RSD of 2.5 to 3.1% and recovery results of 97 to 102%, respectively.

Hexagonal nanostructured cobalt oxide @ nitrogen doped multiwalled carbon nanotubes/polypyyrole composite for supercapacitor and electrochemical glucose sensor

Hexagonal nanostructured cobalt oxide @ N-doped MWCNT /polypyyrole (Co₃O₄/PPy@N-MWCNT) composite was produced by an ultrasonication-mediated solvothermal method for electrochemical supercapacitor and glucose sensor applications. The structural and electrochemical properties of the Co₃O₄/PPy@N-MWCNT were confirmed by various spectroscopic and microscopic techniques. The as-prepared electrode showed an excellent capacitance of ∼872 F/g at 0.5 A/g with a capacitance retention of 96.8 %, even after 10,000 cycles. In addition, analysis of the sensing activity of the composite materials towards the glucose detection showed excellent electrochemical sensing performance that includes the glucose linear limit of (10 to 0.15) μm, detection sensitivity of 195.72 μA/cm²/mM, and lower detection value of S = 0.07327 μA/cm² @ R² = 0.99. The as-prepared composite material can be a promising candidate for the electrochemical supercapacitor and the efficient sensing of glucose.

Investigation of the spectroelectrochemical behavior of quercetin isolated from Zanthoxylum bungeanum

Flavonoids are common bioactive components in plants. Quercetin is the most abundant flavonoid in the human diet, accounting for more than half of the total daily consumption of flavonoids. In this study, adsorption and electrocatalytic activities of quercetin isolated from Zanthoxylum bungeanum on an electrode was studied via homemade electrodes. An in situ UV-Visible thin-layer spectroelectrochemical method was used to study the electrochemical behavior of quercetin in detail and to explore its electrochemical reaction mechanism. This experiment proves that UV-Vis thin-layer spectroelectrochemistry is a feasible way for studying the electrochemical reaction mechanism of flavonoids in plants.

Silver nanoparticles decorated g-C3N4: An efficient SERS substrate for monitoring catalytic reduction and selective Hg2+ions detection

Graphitic carbon nitride supported Ag NPs(AgNPs@g-C₃N₄) were synthesized by an in-situ chemical reduction using a green reducing agent, tannic acid. They were characterized by UV-Vis, FTIR, XPS, XRD, FESEM, EDAX and HRTEM. They were very much SERS sensitive, and capable of detecting methylene blue and 4-aminothiophenol at 1 × 10^-12 M and 1 × 10^-10 M, respectively with the corresponding SERS enhancement factor of 1.4 × 10⁸ and 4.7 × 10⁷. Apart from its high SERS sensitivity, it exhibited high catalytic activity for the reduction of MB with NaBH₄. So, their SERS activity and catalytic activity were combined successfully to monitor catalytic reduction of MB by SERS technique. Further, the SERS activity towards MB was also employed for the detection/quantification of free Hg²⁺ ions in aqueous solution. The SERS intensity of MB drastically decreased in the presence of Hg²⁺ ions, and hence it provides novel route to detect and quantify the latter. Presence of Ca²⁺, Mg²⁺, Cu²⁺ and Cd²⁺ions showed zero interference for it. So, this study proves that Ag NPs@g-C₃N₄ as a unique substrate for multiple SERS applications.

Water-soluble graphitic carbon nitride for clean environmental applications

The removal of halogenated dye and sensing of pharmaceutical products in the water bodies with quick purification time is of high need due to the scarcity of drinking water. The present work reported on the preparation of graphitic carbon nitride (g-C₃N₄) for quick time water contaminant adsorption, followed by synthesizing silver nanoparticles decorated graphitic carbon nitride for pharmaceutical product sensing using in-situ SERS technique. The prepared graphitic carbon nitride is used to study the adsorption behavior of water contaminants at room temperature, in the presence of methylene blue (MB) as an adsorbate model. The water-soluble graphitic carbon nitride, even at low concentration, possesses an excellent ability to adsorb halogenated organic dye. As a result, the dyes are found to adsorb within ∼5s even without any additional physical or chemical activation. From the UV-Vis absorption investigations, it has been perceived that in the presence of graphitic carbon nitride (g-C₃N₄) the dye adsorption efficacy is observed nearly 80% with the well fitted linearly of R² = 0.9731. Effective in-situ surface-enhanced Raman scattering (SERS) studies for Ag nanoparticles decorated graphitic carbon nitride has been carried out and the obtained result shows good sensing performance of the material towards acetaminophen drug. This method opens the possibility of the Nobel metal decorated graphitic carbon nitride for real-time sensing of SERS-based drug products along with the development of high-performance sensing of the target analyte in the future.

Improved conductivity of flower-like MnWO4 on defect engineered graphitic carbon nitride as an efficient electrocatalyst for ultrasensitive sensing of chloramphenicol

Environmental hazards caused by chloramphenicol has attained special attention. Fast, accurate and reliable detection of chloramphenicol in foodstuffs and water samples is of utmost importance. Herein, we developed a g-C₃N₄/MnWO₄ composite for the selective and sensitive detection of chloramphenicol. Successful fabrication of g-C₃N₄/MnWO₄ composite was verified by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and x-ray photo electron spectroscopy (XPS) techniques. Electrochemical characteristics were evaluated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The g-C₃N₄/MnWO₄ modified glassy carbon electrode has shown the highest electrocatalytic activity towards chloramphenicol with a decreased reduction potential of -0.547 V and increased cathodic peak current. The developed sensor has shown excellent performance for the detection of chloramphenicol with a sensitivity of 0.9986 μA nM^-1 cm^-2 and LOD of 1.03 nM in a broad linear range of 4.0-71 nM. In addition, the fabricated sensor has achieved anti-interference ability, good stability, excellent repeatability and remarkable reproducibility for the detection of chloramphenicol. The fabricated sensor applied for the determination of chloramphenicol in milk, human blood serum and sewage samples, in which significant and satisfactory results were achieved.

In situ formed zinc oxide/graphitic carbon nitride nanohybrid for the electrochemical determination of 4-nitrophenol

The electrochemical determination of 4-nitrophenol using a nanohybrid consisting of glassy carbon (GC) and zinc oxide/graphitic carbon nitride (ZnO/g-CN nanosheet), is described. The ZnO/g-CN nanohybrid was in situ synthesized by chemical method and well characterized using absorption spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopic analysis. It was observed that the nanosized ZnO particles were present inside the sheet-like g-CN nanostructure. The nanohybrid-modified electrode showed an enhanced electrocatalytic response for 4-nitrophenol reduction compared with the bare GC electrode. The assay exhibited linear ranges of 13.4-100 μM and 100-1000 μM for 4-NP determination. The limit of detection and limit of quantification were 4.0 and 13.4 μM, respectively, at the working potential of - 0.85 V. An appreciable precision was found towards the stability of the assay in the determination. It provides selectivity against inorganic and organic substances such as calcium chloride, potassium chloride, nitrobenzene, uric acid, 1-chloro,2,4-dinitrobenzene, 1-bromo,2-nitrobenzene and 1-iodo,2-nitrobenzene. The practical applicability of the assay was also checked in the analysis of real water samples and satisfactory recovery of 4-NP was found. Schematic representation of the synthesis of zinc oxide (ZnO) nanostructures incorporated graphitic carbon nitride nanosheets (g-C₃N₄ NSs) and its application in the voltammetric determination of 4-nitrophenol (4-NP) is presented. The nanohybrid assay showed selectivity among coexisting compounds and good recovery in real sample analysis.

Ultrasonically assisted synthesis of barium stannate incorporated graphitic carbon nitride nanocomposite and its analytical performance in electrochemical sensing of 4-nitrophenol

We describe the ultrasonic assisted preparation of barium stannate-graphitic carbon nitride nanocomposite (BSO-gCN) by a simple method and its application in electrochemical detection of 4-nitrophenol via electro-oxidation. A bath type ultrasonic cleaner with ultrasonic power and ultrasonic frequency of 100 W and 50 Hz, respectively, was used for the synthesis of BSO-gCN nanocomposite material. The prepared BSO-gCN nanocomposite was characterized by employing several spectroscopic and microscopic techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, fourier transform infra-red, field emission scanning electron microscopy, and high resolution transmission electron microscopy, to unravel the structural and electronic features of the prepared nanocomposite. The BSO-gCN was drop-casted on a pre-treated glassy carbon electrode (GCE), and their sensor electrode was utilized for electrochemical sensing of 4-nitrophenol (4-NP). The BSO-gCN modified GCE exhibited better electrochemical sensing behavior than the bare GCE and other investigated electrodes. The electroanalytical parameters such as charge transfer coefficient (α = 0.5), the rate constant for electron transfer (k_s = 1.16 s^-1) and number of electron transferred were calculated. Linear sweep voltammetry (LSV) exhibited increase in peak current linearly with 4-NP concentration in the range between 1.6 and 50 μM. The lowest detection limit (LoD) was calculated to be 1 μM and sensitivity of 0.81 μA μM^-1 cm^-2_. A 100-fold excess of various ions, such as Ca²⁺, Na⁺, K⁺, Cl^-, I^-, CO₃^2-, NO₃, NH₄⁺ and SO₄^2- did not able to interfere with the determination of 4-NP and high sensitivity for detecting 4-NP in real samples was achieved. This newly developed BSO-gCN could be a potential candidate for electrochemical sensor applications.

Sr-Doped NiO3 nanorods synthesized by a simple sonochemical method as excellent materials for voltammetric determination of quercetin

A fabricated Sr-doped NiO₃ nanorod-modified GCE was developed for electrochemical sensing of quercetin.