Effects of sonochemical approach and induced contraction of core–shell bismuth sulfide/graphitic carbon nitride as an efficient electrode materials for electrocatalytic detection of antibiotic drug in foodstuffs

Ultrasonic-enhanced surface-active bismuth trisulfide based core–shell nanomaterials were developed and used as an efficient modified electrode material to construct a highly sensitive antibiotic sensor. The core–shell Bi₂S₃@GCN electrode material was directly synthesized by in-situ growth of GCN on Bi₂S₃ to form core–shell like nanostar (Ti-horn, 30 kHz, and 70 W/cm²). The electrocatalyst of Bi₂S₃@GCN nanocomposites was efficaciously broadened towards electrochemical applications. As synthesized Bi₂S₃@GCN promoted the catalytic ability and electrons of GCN to transfer to Bi₂S₃. The single-crystalline GCN layers were uniformly grown on the surface of the Bi₂S₃ nanostars. Under the optimal conditions of electrochemical analysis, the CPL sensor exhibited responses directly proportional to concentrations (toxic chemical) over a range of 0.02–374.4 μM, with a nanomolar detection limit of 1.2 nM (signal-to-noise ratio S/N = 3). In addition, the modified sensor has exhibited outstanding selectivity under high concentrations of interfering chemicals and biomolecules. The satisfactory CPL recoveries in milk product illustrated the credible real-time application of the proposed Bi₂S₃@GCN sensors for real samples, indicating promising potential in food safety department and control. Additionally, the proposed electrochemical antibiotic sensor exhibited outstanding performance of anti-interfering ability, high stability and reproducibility.     

Ultrasonic preparation and nanosheets supported binary metal oxide nanocomposite for the effective application towards the electrochemical sensor

Binary metal oxides (La₂O₃@SnO₂) decorated reduced graphene oxide nanocomposite was synthesized by ultrasound process in an environmentally benign solvent with a working frequency of 25 and 40 kHz (6.5 l200 H, Dakshin, India and maximum input power 210 W). Further, to enhance the electrocatalytic activity, the reduced graphene oxide (rGO) was prepared from graphene oxide by ultrasonication method. As prepared La₂O₃@SnO₂/rGO was scrutinized using XRD, TEM, EDX and quantitative test for the structural and morphology properties. As modified La₂O₃@SnO₂/rGO nanocomposite exhibits better electrochemical activity towards the oxidation of methyl nicotinate with higher anodic current compared to other modified and unmodified electrode for the detection of methyl nicotinate with larger linear range (0.035–522.9 µM) and lower limit of detection (0.0197 µM). In addition, the practical feasibility of the sensor was inspected with biological samples, reveals the acceptable recovery of the sensor in real samples.     

Electrical study of cathodic activation and relaxation of La0,80Sr0,20MnO3

The effect of cathodic activation of sprayed La_0.8Sr_0.2MnO₃ (LSM) films has been studied by electrochemical spectroscopy impedance (EIS). LSM powder was prepared by a citrate route and X-ray diffraction analyses show a complete LSM crystallization without La₂O₃ or La(OH)₃ as side products. Porosity and grain size estimated from scanning electronic microscopy gave values of 33% and 100 nm, respectively. EIS measurement was performed on a Pt/yttria-stabilized zirconia/LSM cell before and after a cathodic current load (300 mA/cm²) on LSM electrode. The relaxation process, which is time-dependent, has been investigated. A drastic decrease of the electrode resistance was noticed just after applying the cathodic current, but after 9 h at optimized valence configuration in air at 850 °C, the recorded polarization resistance gradually enhanced until it almost reached the initial value. The resulting diagrams have been fitted using a Gerischer associated with a resistor and constant phase elements. This simple method has permitted us to observe that only the electrode interfaces are modified by a cathodic activation and the microstructure remains nearly constant.     

SILAR deposited Bi2S3 thin film towards electrochemical supercapacitor

Bi₂S₃ thin film electrode has been synthesized by simple and low cost successive ionic layer adsorption and reaction (SILAR) method on stainless steel (SS) substrate at room temperature. The formation of interconnected nanoparticles with nanoporous surface morphology has been achieved and which is favourable to the supercapacitor applications. Electrochemical supercapacitive performance of Bi₂S₃ thin film electrode has been performed through cyclic voltammetry, charge-discharge and stability studies in aqueous Na₂SO₄ electrolyte. The Bi₂S₃ thin film electrode exhibits the specific capacitance of 289 Fg⁻¹ at 5 mVs⁻¹ scan rate in 1 M Na₂SO₄ electrolyte.     

Green sonochemical synthesis and fabrication of cubic MnFe2O4 electrocatalyst decorated carbon nitride nanohybrid for neurotransmitter detection in serum samples

The binary nanomaterials and graphitic carbon based hybrid has been developed as an important porous nanomaterial for fabricating electrode with applications in non-enzymatic (bio) sensors. We report a fast synthesis of bimetal oxide particles of nano-sized manganese ferrite (MnFe₂O₄) decorated on graphitic carbon nitride (GCN) via a high-intensity ultrasonic irradiation method for C (30 kHz and 70 W/cm²). The nanocomposites were analyzed by powder X-ray diffraction, XPS, EDS, TEM to ascertain the effects of synthesis parameters on structure, and morphology. The MnFe₂O₄/GCN modified electrode demonstrated superior electrocatalytic activity toward the neurotransmitter (5-hydroxytryptamine) detection with a high peak intensity at +0.21 V. The appealing application of the MnFe₂O₄/GCN/GCE as neurotransmitter sensors is presented and a possible sensing mechanism is analyzed. The constructed electrochemical sensor for the detection of 5-hydroxytryptamine (STN) showed a wide working range (0.1–522.6 μM), high sensitivity (19.377 μA μM⁻¹ cm⁻²), and nano-molar detection limit (3.1 nM). Moreover, it is worth noting that the MnFe₂O₄/GCN not only enhanced activity and also promoted the electron transfer rate towards STN detection. The proposed sensor was analyzed for its real-time applications to the detection of STN in rat brain serum, and human blood serum in good satisfactory results was obtained. The results showed promising reproducibility, repeatability, and high stability for neurotransmitter detection in biological samples.     

A comparative study of the Ruddlesden-Popper series,Lan+1NinO3n+1 (n = 1, 2 and 3), for solid-oxide fuel-cell cathode applications

A comparative investigation of the much-studied La₂NiO_4+δ (n = 1) phase and the higher-order Ruddlesden-Popper phases, La_n+1Ni_nO_3n+1 (n = 2 and 3), has been undertaken to determine their suitability as cathodes for intermediate-temperature solid-oxide fuel cells. As n is increased, a structural phase transition is observed from tetragonal I4/mmm in the hyperstoichiometric La₂NiO_4.15 (n = 1) to orthorhombic Fmmm in the oxygen-deficient phases, La₃Ni₂O_6.95 (n = 2) and La₄Ni₃O_9.78 (n = 3). High temperature d.c. electrical conductivity measurements reveal a dramatic increase in overall values from n = 1, 2 to 3 with metallic behavior observed for La₄Ni₃O_9.78. Impedance spectroscopy measurements on symmetrical cells with La_0.9Sr_0.10Ga_0.80Mg_0.20O_3−δ (LSGM-9182) as the electrolyte show a systematic improvement in the electrode performance from La₂NiO_4.15 to La₄Ni₃O_9.78 with ∼ 1 Ω cm² observed at 1073 K for the latter. Long-term thermal stability tests show no impurity formation when La₃Ni₂O_6.95 and La₄Ni₃O_9.78 are heated at 1123 K for 2 weeks in air, in contrast to previously reported data for La₂NiO_4.15. The relative thermal expansion coefficients of La₃Ni₂O_6.95 and La₄Ni₃O_9.78 were found to be similar at ∼ 13.2 × 10^− 6 K^− 1 from 348 K to 1173 K in air compared to 13.8 × 10^− 6 K^− 1 for La₂NiO_4.15. Taken together, these observations suggest favourable use for the n = 2 and 3 phases as cathodes in intermediate-temperature solid-oxide fuel cells when compared to the much-studied La₂NiO_4+δ (n = 1) phase.     

Microstructure and electrode properties of La0.6Sr0.4Co0.2Fe0.8O3-δ spin-coated on Ce0.8Sm0.2O2?δ electrolyte

Fine and uniform La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ powder was synthesized by a glycine–nitrate combustion process. La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ electrodes were prepared on dense Ce_0.8Sm_0.2O_2−δ electrolyte substrates using a spin-coating technique by sintering at 900–1,000 °C. The electrode properties of La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ were investigated by electrochemical impedance spectroscopy and chronopotentiometry techniques with respect to preparation conditions and the resulting microstructures. The results indicate a significant effect of the microstructure on the electrode processes and polarization characteristics. The oxygen adsorption and dissociation process acted as a larger contribution to the overall electrode polarization R _p in magnitude compared with the charge transfer process due to relatively low porosity levels of the electrodes. It was detected that the grain size of the electrodes exhibited a crucial role on the electrocatalytic reactivity. At 800 °C, the electrode sintered at 950 °C attained a polarization resistance of 0.18 Ω cm², an overpotential of 27 mV at a current density of 200 mA cm⁻², and an exchange current density of 308 mA cm⁻².     

Oxygen electrodes of zirconia electrolytes: fundamentals and application to analysis of oxygen containing gases

The kinetics of the oxygen exchange reaction and the reduction of NO at La_0.8Sr_0.2CoO₃−, La_0.8Sr_0.2MnO₃− and Ag-electrodes on stabilized zirconia (8mol% Y₂0₃=YSZ) has been studied by means of electrochemical methods (impedance, I-U characteristics). For La_0.8Sr_0.2CoO₃ electrodes the oxygen exchange was found to proceed via the bulk of the electrode with a rate limiting oxygen exchange at the electrode surface. Electrodes based on La_0.8Sr_0.2MnO₃ change their electrode characteristics with the applied potential. At low cathodic polarization the electrode reaction is limited to the three-phase boundary electrode/YSZ/gas. At high cathodic potentials oxygen vacancies are created and consequently additional oxygen is exchanged via the electrode bulk. Furthermore, a significant NO reduction was observed which indicate a reaction with the oxygen vacancies at the electrode surface. For Ag a rate limiting transport of oxygen atoms through the bulk of the electrode was found. As a consequence the oxygen concentration at the electrode surface remains nearly constant. In this context, the observed inactivity for the NO reduction of Ag-electrodes may be explained. Paper presented at the 2nd Euroconference on Solid State Ionics, Funchal, Madeira, Portugal, Sept. 10–16, 1995     

Maximum magnetic entropy change modulated toward room temperature in perovskite manganites La0.7−xNdx(Ca,Sr)0.3MnO3

With Nd³⁺ doping and Ca²⁺, Sr²⁺ modulating in the sol–gel technique, a series of polycrystalline perovskite samples La_0.7?xNd_x(Ca,Sr)_0.3MnO₃ (x = 0, 0.05, 0.1, 0.15, 0.20, 0.25) was prepared, their maximum magnetic entropy changes were tuned to room temperature (ΔS_H = ?1.47 J/kg K at 298 k for La_0.45Nd_0.25(Ca,Sr)_0.3MnO₃), an enhancement of the maximum magnetic entropy change (ΔS_H = ?1.89 J/kg K at 315 k) and its refrigerant capacity (about 45.3 J/kg) had also been obtained under 9 kOe magnetic field variation for La_0.55Nd_0.15(Ca,Sr)_0.3MnO₃ contrast to La_0.7(Ca,Sr)_0.3MnO₃.     

Effect of Na and Mn substitution in perovskite type LaFeO3 for storage device applications

The feasibility of perovskite-type La_0.8Na_0.2Fe_0.8Mn_0.2O₃ for structural, electrical, and electrochemical property for high rate capability in supercapacitor has been explored at room temperature. Nanocrystalline La_0.8Na_0.2Fe_0.8Mn_0.2O₃ was prepared via a modified Pechini route. Structural and surface morphology was done by X-ray diffraction and field emission scanning electron microscopy, respectively. Optical band gap was evaluated to be ∼1.59 eV. The bulk conductivity of the electrode under study was found to be ∼4.54 × 10⁻⁷S cm⁻¹. Specific surface area was found to be ∼8.16 m² g⁻¹. The electrode property has been studied via cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and charge-discharge analysis. The presence of a redox peak in cyclic voltammetry reveals typical pseudocapacitor behavior and recorded in the potential window −0.35 to 1 V. Faradic charge transfer resistance (R_ct) was found to be ∼53.85 Ω (R_s = 2.03 Ω) from EIS, and the charge-discharge characteristic for a hundred cycles shows an initial capacity fading up to 25 cycles, beyond which it becomes stable at ∼6.2 Fg⁻¹.

     

Highly sensitive ethanol sensors based on nanocrystalline SnO2 thin films

This paper reports on a simple and inexpensive ultrasonic spray pyrolysis method to synthesize agglomerate-free nanosized SnO₂ particles with a size smaller than 10 nm. Scanning electron microscopy, transmission electron microscopy and high resolution X-ray diffraction studies were used to characterize the morphology, crystallinity, and structure of the SnO₂ particles. Under the optimized experimental conditions, the prepared SnO₂ sensor shows the high response (S = 491) towards 100 ppm ethanol gas at 300 °C, linearity in the range of 100–500 ppm, quick response time (2 s), recovery time (60 s) and selectivity against other gases. The response of the sensor was monitored in a 250–450 °C temperature range. The seven fold enhancement in gas response and selective detection of C₂H₅OH in the presence of other gases such as CH₃OH and CH₃CHOHCH₃ are the significant points in this investigation. These results demonstrate that pure nanocrystalline SnO₂ thin film can be used as the sensing material for fabricating high performance ethanol sensors.     

Rate limiting steps of the porous La0.6Sr0.4Co0.8Fe0.2O3−δ electrode material

The electrode reaction of porous La_0.6Sr_0.4Co_0.8Fe_0.2O_3?δ films deposited onto Ce_0.9Gd_0.1O_1.95 (CGO) was investigated by impedance spectroscopy within the temperature and oxygen partial pressure (pO₂) ranges of 500 ≤ T ≤ 700 °C and 10^? 4 < pO₂ < 1 atm, respectively, using Ar and He as gas carriers. The electrochemical impedance spectroscopy (EIS) measurements reveal a high frequency (HF) and a low frequency (LF) regions in the Nyquist plane. The high frequency (HF) region was fitted with a Warburg-type impedance element, and the low frequency (LF) region was reproduced with a resistance in parallel to a constant phase element. Both, the slight dependence of the polarization resistance (R_W) and the small variation of the apex frequency (f_v) of the HF Warburg-type element, on pO₂, suggest that this contribution corresponds to the oxygen diffusion in the bulk of the La_0.6Sr_0.4Co_0.8Fe_0.2O_3?δ electrode material. The variation of the polarization resistance of the LF region (R_rcpe) with pO₂ indicates that as T increases, the limiting step evolves from dissociative oxygen adsorption to oxygen gas diffusion in the pores of the mixed ionic/electronic conductor (MIEC) electrode.     

Preparation and characterization of spherical La-doped Li4Ti5O12 anode material for lithium ion batteries

The lithium secondary batteries with high power density need the electrode materials with both high specific capacity and high tap density. An “outer gel” method by TiCl₄ as the raw material has been developed to prepare spherical precursor. High tap density spherical Li₄Ti₅O₁₂ is synthesized by sintering the mixture of precursor and Li₂CO₃. La-doped Li₄Ti₅O₁₂ is also prepared by this method. X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, tap density testing, and the determination of the electrochemical properties show that the Li₄Ti₅O₁₂ powders prepared by this method are spherical and exhibits high tap density. La³⁺ dopant improved the electrochemical performance over the pristine Li₄Ti₅O₁₂. It is tested that the tap density of the pristine and La³⁺-doped products is as high as 1.80 and 1.78 g•cm⁻³, respectively. Between 1.0 and 3.0 V versus Li, the initial discharge capacity of the La³⁺ dopant is as high as 161.5 mAh•g⁻¹ at 0.1C rate. After 50 cycles, the reversible capacity is still 135.4 mAh•g⁻¹.     

Equilibrium of 1:2:3 CLBLCO superconductors with oxygen: reaction equation,thermodynamics and improvement of homogeneity

Equilibrium of 1:2:3 superconductors (Ca_xLa_1−x)(Ba_1.75−xLa_0.25+x)Cu₃O_y (this compound has in the past variously denoted as CLBLCO, CLBCO or CaLaBaCuO) with oxygen was studied for x=0.1 and x=0.4 in the temperature range of 150–950 °C under 1 atm. O₂. The main process is the reversible reaction −Cu₃²⁺O_6.625+0.25O₂=−Cu₂²⁺Cu³⁺O_7.125 which is completed with the formation of one Cu³⁺. The enthalpy (in kJ/mol CLBLCO) and entropy (in J(mol CLBLCO)⁻¹K⁻¹) of this reaction were calculated from the temperature dependence of the equilibrium constant. The values are ΔH=−33.1 and ΔS=−29.9 for x=0.1 and ΔH=−49.4 and ΔS=−42.7 for x=0.4.It was found that the equilibrium of ceramic pellet of CLBLCO with oxygen cannot be practically achieved below 300 °C while the equilibrium for powder is achieved even at 200 °C. Low rate of reaction of CLBLCO with oxygen causes the problem in low temperature equilibration. In contrast, diffusion of oxygen ions in the ceramics is observed even at 200 °C. This diffusion proceeds without the change of the oxygen content and may be applied in order to improve the homogeneity of the distribution of oxygen ions.     

Magnetocaloric effect in Y-doped La0.6Ca0.4MnO3 enhanced by Griffiths phase and re-entrance of first-order phase transition

It has been known that bulk La_0.6Ca_0.4MnO₃ is an intermediate material of the first- and second-order characters with the tricritical-point exponents, and the doping of a metal ion in it usually causes a continuous second-order transition. The present work reports the re-entrance of a discontinuous first-order transition in orthorhombic La_0.6-xY_xCa_0.4MnO₃ (x = 0.03–0.09) compounds. This enhances the magnetocaloric effect. For the field H = 30 kOe, the maximum magnetic-entropy change (|ΔS_max|) and relative cooling power (RCP) have been evaluated being about 5.45–6.3 J/kg·K and 130–185 J/kg, respectively. If combining these compounds as refrigerant blocks in a rotary ring model, a magnetic cooling device can operate at temperatures T = 85–280 K, with |ΔS_max| ≈ 5.5 J/kg⋅K and RCP ≈ 1073 J/kg. Aside from the re-entranced first-order phase transition, the magnetization and structural analyses have proved the enhanced magnetocaloric effect in La_0.6-xY_xCa_0.4MnO₃ related to a Griffiths singularity, and local Jahn-Teller distortions of the perovskite structure (since the Mn³⁺/Mn⁴⁺ ratio and orthorhombic structural phase are unchanged vs. x).     

A sonochemical assisted synthesis of hollow sphere structured tin (IV) oxide on graphene oxide sheets for the low-level detection of environmental pollutant mercury in biological samples and foodstuffs

In modern approaches for nanomaterials synthesis, ultrasonication plays an important role in providing the larger surface area and smaller crystalline size properties that are favorable to electrochemical techniques. Herein, we report the tin (IV) oxide on graphene oxide nanoparticles were synthesized (SnO₂@GO NPs) by ultrasonic methodology (UZ SONOPULS HD 3400 Ultrasonic homogenizer) with the total power of 400 W and the (frequency of 20 kHz; 140 W/dm³). The formation of as-prepared SnO₂@GO NPs and its surface morphology were scrutinized over XRD, XPS, TEM, and FESEM. Besides, the sonochemically prepared SnO₂@GO NPs were employed for the determination of environmental hazardous mercury (Hg). As a result, the modified electrode acquired a very low-level detection limit of 1.2 nM with a wider range of 0.01–10.41-µM and 14.52–225.4-µM for the detection of Hg. Finally, the practical applicability of SnO₂@GO NPs in spiked human blood serum and tuna fish samples shows appreciable found and recovery values..     

The use of the platinum electrode coated with ultrathin poly(allylamine hydrochloride)/Nafion films for selective detection of hydrogen peroxide

In this paper, a novel polyelectrolyte multilayer (PEM) film-coated platinum electrode for the selective detection of H₂O₂ was presented. The PEM film was formed by the layer-by-layer assembly technique. The quartz crystal microbalance experiments showed that the thickness of the prepared Nafion layer was about 8 nm and depended on the pH of poly(allylamine hydrochloride) solution. The combination of different polyanions and polycations layers was investigated, and it is found that ploy(allylamine hydrochloride) (PAH) and Nafion composited film functioned best as a diffusion barrier toward uric acid (UA) and ascorbic acid (AA) while allowed H₂O₂ to pass through smoothly. When the platinum electrode coated with two-bilayer film, (PAH/Nafion)₂, the amperometric responses of 0.1 mM UA and 0.1 mM AA were respectively 0.008 and 0.006 μA, which were only 0.2% or less of the response of 0.1 mM H₂O₂ (4.0 μA). The linear response range of the electrode toward H₂O₂ was from 1.0 μM to 1.0 mM, and the detection limit was 0.3 μM. The electrode also displayed high operational stability and long-term storage stability.     

Sonochemical synthesis and fabrication of perovskite type calcium titanate interfacial nanostructure supported on graphene oxide sheets as a highly efficient electrocatalyst for electrochemical detection of chemotherapeutic drug

In green approaches for electrocatalyst synthesis, sonochemical methods play a powerful role in delivering the abundant surface areas and nano-crystalline properties that are advantageous to electrocatalytic detection. In this article, we proposed the sphere-like and perovskite type of bimetal oxides which are synthesized through an uncomplicated sonochemical procedure. As a yield, the novel calcium titanate (orthorhombic nature) nanoparticles (CaTiO₃ NPs) decorated graphene oxide sheets (GOS) were obtained through simple ultrasonic irradiation by a high-intensity ultrasonic probe (Titanium horn; 50 kHz and 60 W). The GOS/CaTiO₃ NC were characterized morphologically and chemically through the analytical methods (SEM, XRD, and EDS). Besides, as-prepared nanocomposites were modified on a GCE (glassy carbon electrode) and applied towards electrocatalytic and electrochemical sensing of chemotherapeutic drug flutamide (FD). Notably, FD is a crucial anticancer drug and also a non-steroidal anti-androgen chemical. Mainly, the designed and modified sensor has shown a wide linear range (0.015–1184 µM). A limit of detection was calculated as nanomolar level (5.7 nM) and sensitivity of the electrode is 1.073 μA μM⁻¹ cm⁻². The GOS/CaTiO₃ modified electrodes have been tested in human blood and urine samples towards anticancer drug detection.     

Studies on the percolation limit of Ce0.9Gd0.1O1.95 in La0.6Sr0.4Co0.2Fe0.8O3−δ–Ce0.9Gd0.1O1.95 nanocomposites for solid oxide fuel cells application

A large difference in thermal expansion coefficient of electrode and electrolyte leads to imperfect electrode/electrolyte interface and hence significant polarization losses in solid oxide fuel cells. To overcome the difficulties associated with electrode and electrode/electrolyte interface, there is need to fabricate the composite cathode. Thus the present paper deals with study of La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ(LSCF)–Ce_0.9Gd_0.1O_1.95(GDC) nanocomposite with different fractions of GDC obtained by physical mixing of combustion synthesized nanopowders. No secondary phases were observed upon sintering at 1100 °C for 2 h affirming the chemical compatibility between LSCF and GDC. The composites with relatively high GDC% have higher density as a consequence of rapid grain growth and less conductivity. The nanocomposite with 50% of GDC showed electric conductivity of 30 Scm⁻¹ at 500 °C and low area specific resistance of 106 Ω cm² with 10 μs relaxation time at 200 °C.     

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⁻, CO₃²⁻, NO₃, NH₄⁺ and SO₄²⁻ 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.