Transmission Raman Spectroscopy Research Articles

Physicochemical Characterization of Aerosols in the Coastal Zone: Evidence of Persistent Carbon Soot in the Marine Atmospheric Boundary Layer (MABL) Background

Aerosol particles in coastal areas result from a complex mixing between sea-spray aerosols locally generated at the sea surface by breaking waves and a continental component issued from natural and/or anthropogenic sources. The aim of this paper is to study how the aerosols mix in the coastal marine atmosphere to evaluate the impact of the background pollution on the atmospheric aerosols. To this end, we have carried out a qualitative analysis of particulate matter sampled at two French coastal areas using a non-destructive methodology combining scanning electron microscopy (SEM)/X-ray fluorescence, transmission electron microscopy (TEM), X-ray diffraction, and Raman spectroscopy. Our analysis shows a dominant contribution of anthropogenic aerosols through strong levels of submicronic carbon soot and sulfate particles, even observed when the aerosol is sampled during pure maritime-air mass episodes. Our results also evidence the non-mixing between sea-spray, mainly composed of coarse aerosol particles, and this anthropogenic particulate matter of smaller sizes.

Impact of zinc structural on the photovoltaic Properties of iron Pyrite

FeS2 pyrite is one of the most interesting photovoltaic materials with low-cost and natural abundance but with small band gap of 0.95 eV. In the present work, we show the feasibility of increases band gap was determined by Zinc alloying of Iron pyrite. We showed that we can increase the band gap of FeS2 pyrite to 1.15eV by theoretical calculation and to 1.16eV using experimental method, by just adding a very small amount of Zinc (1%). We prepared our samples by chemical vapor transport technic and we utilized the technic of linear muffin-tin orbital method in the atomic-sphere approximation (LMTO-ASA). The effect of Zinc alloyed Iron pyrite were examined by transmission electron micrograph TEM, XRD, Raman spectroscopy and optical characterization.

Defect structures as a function of ion irradiation and annealing in LiNbO3

Ion implantation is commonly utilized during the fabrication of lithium niobate (LiNbO3) acousto- and opto-electronic devices. Mechanistically, implantation creates material defects affecting properties that can be leveraged to create functionality. Enhancing scalability and the repeatability of these implantation protocols therefore necessitates linking process parameters of implantation with those defects created and ultimately the properties imparted by these defects. In response, we systematically examined the effects of ion species (H, He, and N), irradiation energy (150 keV to 2 MeV), implantation fluence (1 × 1012 to 1 × 1018 ions/cm2), and post-irradiation heat treatment (250 to 750 °C) in 128° Y-cut LiNbO3. The resulting defect structures were then analyzed via transmission electron microscopy and Raman spectroscopy. Defect formation suitable for fracture-based processes can be achieved with implantation of He ions, using an implantation fluence of 1 × 1018 ions/cm2 and a heat treatment at 250 or 500 °C. Other irradiation and annealing recipes that mimic material fabrication conditions show the defect evolution in LiNbO3 dependent on irradiation conditions.

Photocatalytic degradation of orange II dye via high pore volume polymorph zirconium-doped titania under visible light irradiation

A series of mixed-phase Zr-doped TiO2 was utilized for the photocatalytic degradation of orange II dye. These materials were synthesized through a sol–gel technique by varying the amounts of zirconium in the photocatalysts. These materials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray fluorescence (XRF), Raman spectroscopy, thermogravimetry analysis (TGA), and X-ray photoelectron spectroscopy (XPS) among others. XRF and XPS data showed that the elemental composition of the photocatalysts consists of zirconium, titanium, and oxygen. In addition, XRD and Raman spectroscopy confirmed the existence of anatase and rutile phases of TiO2. The TGA analyses showed that the undoped TiO2 was the most stable, with no significant weight loss during the heating range. Furthermore, the materials can effectively degrade orange II dye solution up to 7 cycles through asymmetric cleavage of the azo bond.

Design and tribological performance of CrN/Mo2N/MoSx composite coating in wide temperature range inspired by oxidation kinetics principle

Inspired by oxidation kinetics principle, a series of CrN/Mo2N/MoSx composite coatings with different compositions were prepared by magnetron sputtering technology. Microstructure, chemical composition and mechanical were systematically investigated. The friction and wear behaviors of the CrN/Mo2N/MoSx coatings sliding against Al2O3 ceramic ball at 25–750 ℃ were also evaluated by a ball-on-disc tester (load: 2 N, frequency: 5 Hz, sliding distance: 5 mm). X-ray diffraction, transmission electron microscope and Raman spectroscopy were used to thoroughly analyzed for wear tracks at different temperatures to reveal the mechanism of low wear of the composite coating. Results showed that all of the coatings exhibit polycrystalline structures and the morphologies grow in an obvious columnar crystal. The CrN/Mo2N/MoSx composite coating presented a wear rate as low as 1.62 × 10−6 mm3/Nm and 6.63 × 10−7 mm3/Nm at 25 ℃ and 750 ℃, respectively. It is noted that MoS2 and Mo2N were preferential oxidation in comparison to CrN was conducive to lubrication at medium and high temperature. Additionally, a continuous protective glaze layer was generated within the wear track of the composite coating at 750 ℃ which was mainly consist of MoO3 generated in situ by the oxidation of Mo compounds with a higher affinity for oxygen. Meanwhile, the hard phase of CrN with outstanding oxidation resistance play a good bearing role during the friction process. This new type of composite coating provides a potential solution for the application of high-temperature wear-resistant coating under harsh working conditions for mechanical engineering.

Loops at carbon edges: Boron-assisted passivation and tunable surface properties of carbon nanofibers

During thermal treatment of carbon materials, unstable edge sites can easily convert to structurally stable loop structures. Hence, in the present work, carbon edges are physically passivated via high-temperature treatment in the presence of boron atoms to accelerate loop formation. The highly accelerated loop formation, along with stacking multi-layers at the carbon edges, is systematically investigated via high resolution transmission electron micro microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and thermal gravimetric analysis (TGA). The boron-added carbon nanofibers (CNFs) at high temperature exhibit a greatly enhanced electrical conductivity due to the high mobility of boron atoms within the carbon structure. In particular, engineering of the loop structures on the carbon edges can alter the overall electrocatalytic activities of the carbon-based materials, as demonstrated in the reductive conversion of 4-nitrophenol (4-NP) and in the hydrogen evolution reaction (HER). This work not only suggests suitable methods for carbon edge passivation, but also opens up a route towards the advanced design of high-stability carbon materials in various fields.

Study of Defect-Induced Chemical Modifications in Spinel Zinc-Ferrites Nanostructures by In-Depth XPS Investigation

Spinel zinc ferrite nanomaterials with exceptional physiochemical properties are potential candidates for various applications in the energy and environmental fields. Their properties can be tailored using several methods to widen their applications. The chemical combustion approach was followed to prepare the spinel zinc ferrite nanomaterials, which were then subjected to thermal treatment at a fixed temperature. Thermal heat treatment at a fixed temperature was used to evaluate the phase and morphological characteristics of the prepared spinel zinc−ferrite nanocomposites. Various techniques were employed to examine the samples, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS and X-ray−induced Auger electron spectroscopy were used to extensively examine the surface characteristics of the zinc−ferrite. To study the actual chemical states of the synthesized spinel zinc ferrite nanomaterials and the defects created during the thermal treatment, an extensive investigation of the kinetic energy of the X-ray−induced Zn L3M45M45 and Fe L3M45M45 was conducted. Finally, a detailed analysis of the Wagner plot using the modified Auger parameter was performed to verify the exact chemical states of Zn and Fe. Thus, the findings of the investigation show that XPS is a promising and powerful technique to study the composition and chemical states of spinel zinc ferrites, providing an understanding of changes in their properties for functional applications.

Backscattering and transmission Raman spectroscopy systems in the quantitative analysis concentration of acetone solutions

Raman spectroscopy is a set of techniques based on Raman scattering properties, widely applied to analyze the composition of various substances. The techniques consist of 1) backscattering, which collects Raman signals scattered from the surface of a sample; and 2) transmission, which collects Raman signals transmitted by the surface of a sample in the opposite direction of a light source (which triggers less fluorescence than backscattering). In this paper, we will measure the Raman spectrum of acetone solution by the transmission Raman spectroscopy and the backscattering Raman spectroscopy systems that we set up. Those accessories we use are a 532-nanometer diode laser with 100 milliwatt power as the light source, a focusing lens, an objective lens used for amplifying the Raman signals scattered from the sample, and a long-pass filter used to block light with a wavelength shorter than 532 nanometers. For the experimental samples, there are acetone solutions each prepared at 1M, 3M, 5M, 7M, 9M, 11M, and 13M. In the results of this experiment, we found that the intensity of Raman peaks for each Raman shift of acetone and the molar concentrations of acetone measured by both systems have a linear function in the backscattering Raman system and have a quadratic function in the transmissions Raman system because in backscattering system have noise by fluorescence effect more than in transmission system and it might be the effect of the Beer-Lambert law.

Influence of electrode processing and electrolyte composition on multiwall carbon nanotube negative electrodes for sodium ion batteries

Nanostructured one-dimensional multiwall-carbon nanotubes have a variety of advantageous properties including good electrical conductivity and mechanical strength, and thus have been widely investigated for use in lithium-ion battery electrodes as conductive and microstructural additives, though they also possess some electrochemical activity. Their application to sodium-ion batteries has been less extensively researched, and therefore a greater understanding of the electrochemical reaction with sodium, and effects of slurry composition and electrolyte formulation is warranted, especially as these are likely components in future Na-ion electrode formulations. Here, we report the fabrication of aqueous and organic multi-wall carbon nanotube (MWCNT) negative electrodes processed by ball milling. The binder of choice is noted to greatly affect the electrochemical performance, both in terms of capacity retention and rate capability over a range of current densities from 25 to 500 mA g−1. Switching from a carbonate- to diglyme-based electrolyte considerably improves initial coulombic efficiencies (∼10%–60%), attributed to less extensive formation of solid electrolyte interphase, and enables a reversible mechanism with capacities up to 150 mAh g−1 over 100 cycles depending upon the binder used. Ex-situ characterization of the discharged and cycled carbon nanotubes by powder x-ray diffraction, transmission electron microscopy and Raman spectroscopy provide an insight into how MWCNTs undergo sodiation and demonstrate a partially reversible structural transformation during cycling when using the diglyme-based electrolyte. This work lays the foundation for a better understanding of these versatile materials, especially when used in the most promising alternative energy storage technology to lithium ion.

Heteroatomic stitching of broken WS2 monolayer with enhanced surface potential.

Sub-nanometre thick two-dimensional (2D) materials suffer from severe cracking during the high temperature chemical vapour deposition growth process. The cracking can be utilised to generate more active edges. These active edges can be stitched with a homo- or hetero-material. While the direct growth of 2D-heterostructures is mostly limited to a small fraction of outer edges of monolayer flakes, the cracked monolayers can be utilised to produce a large fraction of heterostructures. Heterostructures are important for developing multifunctional components for nanoscale electronics and optoelectronics. In this work, we demonstrate the formation of WS2-MoS2 heterostructures in large fractions by atomic stitching of cracked WS2 monolayers with the sequential growth of MoS2. Aberration-corrected scanning transmission electron microscopy and Raman spectroscopy have been utillised to probe fine details on the stitched interface between WS2 and MoS2. Growth of MoS2 domains were observed to take place at the terminating edge of cracked WS2, which then merged to form MoS2 multilayers at the cracked site. Growth of MoS2 at the opposite edges of WS2 eventually results in a MoS2-MoS2 junction with a Σ = 7 tilt boundary. Kelvin probe force microscope (KPFM) measurement from the stitched region revealed that the work function of WS2 is ∼32.46 meV higher than that of MoS2, which also closely matches with the Fermi energy difference between these two materials. With the aid of an atomic force microscope and KPFM, the surface potential width at the stitched region was found to be ∼5 times higher than the actual width of the interface, confirming the modulation of properties near the interface.

Nanocrystalline TiO2/Ti3C2Tx MXene composites with a tunable work function prepared using atmospheric pressure oxygen plasma.

Composites of TiO2 and Ti3C2Tx MXene are of great interest because they combine superior TiO2 photocatalytic activity with excellent MXene conductivity. As these composites have conventionally been prepared using methods requiring high temperatures, a process for producing similar materials at reduced temperature could be beneficial for applications in flexible and printed electronics. Therefore, we used low-temperature dielectric barrier discharge to develop a method for forming crystalline TiO2 by treating Ti3C2Tx MXene surfaces with high-power-density oxygen plasma comprising various energetic and reactive oxygen species, which oxidize MXene surfaces and form TiO2 nanoparticles on disordered graphitic carbon sheets within a few seconds. Scanning electron microscopy was used to observe the plasma-induced morphological changes to elucidate the TiO2 formation mechanism. The MXene surface chemistry was studied in detail using X-ray photoelectron spectroscopy and ab initio modelling. The crystalline phase of TiO2 was further studied using transmission electron microscopy and Raman spectroscopy. The results presented here suggest the formation of small anatase nanoparticles on the surface of MXenes within just seconds of plasma exposure. Nanoparticles grew with prolonged plasma treatment and a transition from anatase to rutile was observed. Considering that the temperature of plasma was always below 70 °C, the oxygen plasma process for the preparation of TiO2/Ti3C2Tx composites is an excellent candidate for application on temperature-sensitive substrates in flexible and printed electronics.

Characterization and Modelling of Nanomaterials Synthesized by Chemical Vapor Deposition

In recent years, Chemical Vapor Deposition (CVD) has emerged as a pivotal technique for the synthesis of high-quality nanomaterials, owing to its ability to produce uniform and scalable thin films with controlled properties. This study presents a comprehensive characterization and modelling of nanomaterials synthesized via CVD, elucidating the intricate relationship between process parameters and the resultant material properties. Utilizing advanced characterization techniques, including Transmission Electron Microscopy (TEM), XPS, and Raman Spectroscopy, we have discerned the morphological, compositional, and structural attributes of the synthesized nanomaterials. The experimental data were subsequently employed to develop a predictive model, leveraging machine learning algorithms, to forecast the properties of nanomaterials based on CVD parameters. The model exhibited high accuracy and can serve as a robust tool for optimizing CVD processes in real-time. Our findings underscore the potential of CVD in tailoring nanomaterial properties for specific applications and provide a foundational framework for researchers and industries aiming to harness the full potential of nanomaterials synthesized via CVD. This work not only advances our understanding of CVD-synthesized nanomaterials but also paves the way for their application in next-generation electronic, photonic, and energy devices.

Effect of Ti and Au buffer layers on controlling the density and wettability of well-aligned ZnO nanorod arrays grown on different substrates.

ZnO nanorod arrays (NRAs) have potential applications as building blocks for nanoscale electronic, optoelectronic, and sensing applications. The density of ZnO NRAs is controlled by a simple low-cost hydrothermal growth process. It is shown that Ti and Au thin buffer layers can be used to control ZnO NRA density up to an order of magnitude on a wide variety of substrates including bare glass AZO, ZnO seeded AZO, FTO and ITO substrates, respectively. We investigate surface morphological, structural and optical properties of ZnO NRAs by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, and photoluminescence spectroscopy measurements, respectively. To highlight the importance of NRA density, wettability measurements show large dependence on density and static water contact angles range from as low as ∼23° to as large as ∼142°. These results indicate that the capability to control the density of ZnO NRAs, and thus their wettability, can have additional implications such as in their use in biosensors, field emission, dye-sensitized solar-cells (DSSCs), and photocatalytic activity in addition to potential light trapping effects over wide spectral ranges.

Enhancing the Polishing Efficiency of CeO2 Abrasives on the SiO2 Substrates by Improving the Ce3+ Concentration on Their Surface

The polishing activity of CeO2 abrasives is enhanced by improving the Ce3+ concentration on their surface. In this study, a series of Ce1–xLaxO2 abrasives with different La3+ doping were prepared. The abrasives were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The effects of La3+ doping on the morphology, size, and Ce3+ concentration of the abrasives were studied. The morphology of the particles changes from sphere to octahedron with the La3+ doping. The lattice expansion of the CeO2 crystal after La3+ doping also significantly improves the Ce3+ concentration on the abrasive surface. However, the Ce3+ concentration on the surface gradually became saturated when the x was 0.2 or more. The polishing performance proved that the material removal rate (MRR) is closely related to the Ce3+ concentration generated by La3+ doping. The MRR of pure CeO2 abrasives with a Ce3+ concentration of 20.53% on a SiO2 substrate is 59.31 nm/min, while the Ce0.7La0.3O2 abrasives with the Ce3+ concentration increased to 34.41% achieved 101.12 nm/min. The polished surface quality was characterized by atomic force microscopy, which shows improved roughness of all samples. Furthermore, the differences in the removal rate of Ce3+ and Ce4+ in CeO2-based abrasives on the SiO2 substrate were also discussed.

InVivo Surface-Enhanced Transmission Raman Spectroscopy under Maximum Permissible Exposure: Toward Photosafe Detection of Deep-Seated Tumors.

The detection of deep-seated lesions is of great significance for biomedical applications. However, due to the strong photon absorption and scattering of biological tissues, it is challenging to realize invivo deep optical detections, particularly for those using the safe laser irradiance below clinical maximum permissible exposure (MPE). In this work, the combination of ultra-bright surface-enhanced Raman scattering (SERS) nanotags and transmission Raman spectroscopy (TRS) is reported to achieve the non-invasive and photosafe detection of "phantom" lesions deeply hidden in biological tissues, under the guidance of theoretical calculations showing the importance of SERS nanotags' brightness and the expansion of laser beam size. Using a home-built TRS system with a laser power density of 0.264Wcm-2 (below the MPE criteria),wesuccessfully demonstrated the detection of SERS nanotags through up to 14-cm-thick exvivo porcine tissues, as well as invivo imaging of "phantom" lesions labeled by SERS nanotags in a 1.5-cm-thick unshaved mouse under MPE. This work highlights the potential of transmission Raman-guided identification and non-invasive imaging toward clinically photosafe cancer diagnoses.

Polyethyleneimine-Starch Functionalization of Single-Walled Carbon Nanotubes for Carbon Dioxide Sensing at Room Temperature.

There is an ever-growing interest in the detection of carbon dioxide (CO2) due to health risks associated with CO2 emissions. Hence, there is a need for low-power and low-cost CO2 sensors for efficient monitoring and sensing of CO2 analyte molecules in the environment. This study reports on the synthesis of single-walled carbon nanotubes (SWCNTs) that are functionalized using polyethyleneimine and starch (PEI-starch) in order to fabricate a PEI-starch functionalized SWCNT sensor for reversible CO2 detection under ambient room conditions (T = 25 °C; RH = 53%). Field-emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy are used to analyze the physiochemical properties of the as-synthesized gas sensor. Due to the large specific surface area of SWCNTs and the efficient CO2 capturing capabilities of the amine-rich PEI layer, the sensor possesses a high CO2 adsorption capacity. When exposed to varying CO2 concentrations between 50 and 500 ppm, the sensor response exhibits a linear relationship with an increase in analyte concentration, allowing it to operate reliably throughout a broad range of CO2 concentrations. The sensing mechanism of the PEI-starch-functionalized SWCNT sensor is based on the reversible acid-base equilibrium chemical reactions between amino groups of PEI and adsorbed CO2 molecules, which produce carbamates and bicarbonates. Due to the presence of hygroscopic starch that attracts more water molecules to the surface of SWCNTs, the adsorption capacity of CO2 gas molecules is enhanced. After multiple cycles of analyte exposure, the sensor recovers to its initial resistance level via a UV-assisted recovery approach. In addition, the sensor exhibits great stability and reliability in multiple analyte gas exposures as well as excellent selectivity to carbon dioxide over other interfering gases such as carbon monoxide, oxygen, and ammonia, thereby showing the potential to monitor CO2 levels in various infrastructure.

Fast quantification of diclofenac sodium content in commercially available tablets by transmission Raman spectroscopy with PLS

AbstractA new technology based on transmission Raman spectroscopy was developed for the determination of diclofenac sodium (DS) in commercially available tablets using chemometric tools such as partial least squares (PLS). Based on multifactor orthogonal design of experiment (DOE), we established an initial model consisting of 150 handmade tablets. By adding only two commercially available tablets spectra to the initial model, it was successfully applied to the determination of the active pharmaceutical ingredient (API) of three commercially available diclofenac sodium tablets. The results showed that the relative error of content measured by TRS for three brands of tablets was less than 4% and the RSD of 20 commercially available tablets under brand of Ouyi was 0.49%. The method can ensure high accuracy and good repeatability in rapid nondestructive quantitative analysis and can be used as a new technology for quality control on production lines to monitor drugs in real time.

Magnetism Engineering in Antiferromagnetic β-FeOOH Nanostructures via Chemically Induced Lattice Defects

Elongated akaganéite (β-FeOOH) nanostructures were synthesized through a simple hydrothermal route, in which a careful selection of the experimental conditions allows for a tunable length and aspect ratio and concomitantly predetermines the magnetic response. An in-depth structural characterization using transmission electron microscopy, X-ray diffraction, and Raman spectroscopy, jointly with DC magnetic measurements, reveals a complex scenario where the interstitial Cl– content dictates the β-FeOOH thermal stability and leads to the formation of bulk uncompensated spins along the inner channels. The coexistence of different magnetic contributions is observed to result in a non-monotonic dependence of the coercivity and exchange bias field on both temperature and size, posing major limitations for the archetypical magnetic core–shell model generally assumed for nanostructured antiferromagnets. As a proof of concept, we further show how the β-FeOOH internal microstructure can be chemically manipulated through Cl– anion exchange, giving rise to a superparamagnetic component that comes along with an almost 20-fold increase in the coercivity at low temperature. The evaluation of these results reveals the potential of controlling the interplay between the crystal and magnetic structure via intercalation chemistry in antiferromagnets, expanding fundamental science knowledge and supporting practical applications, given their huge role in the technological fields of spintronics and magnonics.

Interlacing Rod and Sphere Morphology of MnO2 in RGO/NiO/MnO2 Ternary Nanocomposites for Supercapacitive Applications

Supercapacitors are promising energy storage devices. Herein a comparative study was carried out between two samples of reduced graphene oxide-infused binary metal oxides, in which the morphology of one of the metal oxides (Manganese oxide) is altered. MnO2 was synthesized in two morphologies namely nanorods and nanospheres. The two morphologies (rod and spheres) were separately composited with the as-synthesized cone-structured nickel oxide and sheets of reduced graphene oxide (rGO) and were subjected to various structural, functional, morphological, electrochemical characterizations etc. The morphologies and structures of the as prepared samples were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectrometer (XPS). The functional properties were determined using Fourier Transform Infra-Red (FTIR) Spectroscopy. The electrochemical performance of both the samples were analysed using Cyclic Voltammetry (CV), Galvanostatic Charge/Discharge (GCD) measurements and Electrochemical Impedance Spectroscopy (EIS) under electrolytes with different pH namely 1M Na2SO4(pH = 7) and 1M Na2CO3(pH = 11). The CV was analysed with different scan rates and GCD was taken under 1–5 Ag−1 current densities. The cycling stability of the materials were testified for 5000 cycles of CV and GCD. The results are discussed. The main advantage of this work is that the best suited morphology with better ion transfer rate having commendable electrochemical ability and long-standing cycle rate for a promising supercapacitor is identified which will serve as the reference for the future supercapacitor electrodes.

Graphite-sheathed ZnMn2O4 microspheres for electrochemical detection of As(III)

In the current research work, the authors report the synthesis of ZnMn2O4 microspheres and G@ZnMn2O4 with a facile hydrothermal process followed by calcination. The as-synthesized materials have been used as a cost-effective strategy for the electrochemical detection of As(III). The composites are characterized for structural and morphological advances using X-ray diffraction (XRD), Scanning electron microscopy EDS, High-resolution transmission electron microscopy (HRTEM), Raman Spectroscopy and X-ray photoelectron spectroscopy (XPS). The ZnMn2O4 microspheres and G@ZnMn2O4 showed excellent electrocatalytic activity towards the reduction of As(III). The G@ZnMn2O4 modified electrode attained a sensitivity of 12.528μAppb−1cm−2 with a lower detection limit (LOD) of 0.87 ppb within the range of 0.33 ppb–5.61 ppb.