μA μM Research Articles

A step toward Molnupiravir, COVID-19 Antiviral, detection using Cauliflower-Like cobalt Sulfide-Decorated carbon nanotube modified glassy carbon electrodes

Inhibiting the replication of COVID-19 viruses, Molnupiravir (MOL) has drawn extensive attention as an efficient antiviral medication during the global coronavirus pandemic. Adjusting the antiviral drug dosage is at the leading edge of achieving the optimum therapeutic effects while avoiding unwanted side effects. Developing inexpensive, highly-sensitive analytical methods, benefiting from high reliability and fast response of prime significance in monitoring and quality control of MOL in various matrices. Herein, an innovative strategy is developed to fabricate high-performance MOL sensing platforms through a facile and scalable approach. Accordingly, multi-walled carbon nanotubes (MWCNTs) are first drop-casted on the surface of glassy carbon electrode. Afterward, cauliflower-like cobalt sulfide nanosheets are electrodeposited onto the MWCNT-casted electrode. The MOL-sensing ability of the prepared sensing platforms is evaluated using various electrochemical methods. Under the optimal experimental conditions, two linear responses within broad detection ranges of 0.5 – 16 µM and 16 – 90 µM are obtained using the linear sweep voltammetry technique. A detection limit of 0.16 µM with a maximum sensitivity of 0.63 µA µM−1 in parallel to a relative standard deviation of 6.3 % is also achieved. Having the merit of high MOL sensitivity compared to other coexist interferences in human body fluids, together with fast response time, long-term stability, excellent repeatability, and high reproducibility, makes the fabricated electrode promising for reliable, fast, and accurate MOL monitoring.

Amplifying Flutamide Sensing through the Synergetic Combination of Actinidia-Derived Carbon Particles and WS2 Platelets.

The development of electrochemical sensors for flutamide detection is a crucial step in biomedical research and environmental monitoring. In this study, a composite of Actinidia-derived carbon particles (CPs) and tungsten disulfide (WS2) was formed and used as an electrocatalyst for the electrochemical detection of flutamide. The CPs had an average diameter of 500 nm and contained surface hydroxyl and carbonyl groups. These groups may help anchor the CPs onto the WS2 platelets, resulting in the formation of a CPs-WS2 nanocomposite with a high surface area and a conducting network, enabling electron transfer. Using the CPs-WS2 composite supported at a glassy carbon electrode, a linear concentration range extending from 1 nM to 104 μM, a limit of detection of 0.74 nM, and a sensitivity of 26.9 ± 0.7 μA μM-1 cm-2 were obtained in the detection of flutamide in a phosphate buffer. The sensor showed good recovery, ranging from 88.47 to 95.02%, in river water samples, and exhibited very good selectivity in the presence of inorganic ions, including Al3+, Co2+, Cu2+, Fe3+, Zn2+, NO3 -, SO4 2-, CO3 2-, and Cl-.

Construction of 3D spinel binary metal oxide flower decorated 1D halloysite nanotube electrocatalyst for the selective detection of arsenic drug pollutant roxarsone

Heavy metals, including arsenic (As), are categorized as a Group I toxic carcinogen and pose significant threats to the environment and habitats. Roxarsone (RXN) is an organoarsenic antibiotic drug commonly employed as a veterinary curative agent and growth promoter for poultry. Due to its widespread use, it substantially contributes to the accumulation of As in humans and ecosystems. Therefore, it is essential to monitor this potential drug in various real-world samples with high accuracy. Consequently, we have designed 3D zinc cobalt oxide (ZCO) with a 1D halloysite nanotube (HNT) based electrochemical sensor. The functional and morphological features of the electrocatalysts were evaluated with numerous analytic methods. The electrocatalytic property was investigated with different voltammetric measurements. Based on the outcomes, our ZCO/HNT-modified sensor displayed good linear ranges (0.01 to 127 μM and 127 μM to 1147 μM), low detection (1.6 nM), and quantification (5.2 nM) limits, optimal sensitivity (0.465 μA μM−1 cm−2), good selectivity, remarkable performance, and good stability results. Further, this sensor was applied to monitor RXN in various real-world samples and consequently, obtained the well-resolved results. Hence, our ZCO/HNT is an efficacious electrocatalyst for the precise detection of RXN.

Silver bismuth sulphide (AgBiS2)-MXene composite as high-performance electrochemical sensing platform for sensitive detection of pollutant 4-nitrophenol

4-Nitrophenol (4-NP) is one of the most common and extensive toxic threats to the environment; hence there is always a need to develop a robust analytical method. In this study, we present MXene-based AgBiS2 nanocomposite as an electrochemical sensing platform for detecting 4-NP. The synergistic combination of MXene and AgBiS2 within the composite structure enhances electrocatalytic performance, resulting in a highly sensitive and selective sensor. The electrochemical performance of the MXene-AgBiS2 modified GCE was evaluated through cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analyses. The sensor exhibited excellent electrochemical properties, including a low detection limit (LOD) of 0.00254 µM (should consider the method how to get such low LOD – due to 10 times of the lowest conc tested S/N = 3, high sensitivity of 5.862 µA µM−1 cm−2, and a wide linear range (0.02–1869 µM). The sensor also demonstrated good selectivity against various interference compounds such as Di-Nitrophenol, Ortho-Nitrophenol, Copper, Cobalt, sodium, Manganese, Zinc, Glucose (GLU), Urea (Ur), Dopamine (DA), Ascorbic acid, and Uric Acid. Along with reproducibility, repeatability, and stability also performed shows, 2.21 %, and 2.71 % respectively. Our nanocomposite sensor, utilizing MXene-based AgBiS2, proves its practicality in real-time tap water analysis. This bridge between lab studies and environmental monitoring marks a significant advancement. The unique properties of our sensor enhance electrochemical sensing, providing a promising solution for swift on-site detection of 4-NP in water, potentially revolutionizing pollutant management.

Lutetium Copper@Hexagonal Boron Nitride Nanocomposite Electrode System for Sensing and Signalling Ciprofloxacin

AbstractHerein, a new electrochemical sensing system based on lutetium copper nanoparticles supported on hexagonal boron nitride (Lu‐Cu@h‐BN) was designed for the sensitive detection of ciprofloxacin (CIP) antibiotic. A simple hydrothermal method was used to synthesize the nanocomposite. The structural and morphological characteristics of the as‐prepared nanocomposite were investigated using various analytical techniques such as Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). The newly developed Lu‐Cu@h‐BN nanocomposite was used as an electrode modifier for sensing and signalling of CIP. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical activities of the bare GCE, Cu‐h‐BN/GCE, Lu‐h‐BN/GCE, Lu‐Cu/GCE, and Lu‐Cu@h‐BN/GCE. The electro‐oxidation of CIP on electrode surface exhibited an irreversible, diffusion‐controlled process. The sensor system obtained a wider linear range of (0.05–100 μM) with a lower detection limit value of 0.03 μM and sensitivity 0.7443 μA μM−1 cm−2. Furthermore, the sensor demonstrated an excellent selectivity, good stability, and reproducibility, with acceptable recoveries of 96 % to 104 % in real water sample analysis.

Nonenzymatic electrochemical detection of endocrine disruptor (Bisphenol-A) based on biogenic α-Fe2O3 nano enabled interface prepared by Bluemea sinuata leaf extract

One of the most important organic monomers in the manufacturing of plastic is bisphenol-A (BPA), which is widely used in food packaging, containers, and water pipelines, among other industries. However, because of how easily it contaminates food and water and causes illnesses, including cancer, heart disease, and developmental abnormalities, its extensive usage carries serious dangers to human health and the environment. BPA is nevertheless widely used in numerous products despite its negative effects. A new technique using α-Fe2O3 nanoparticles synthesized from Bluemea sinuate leaf extract is offered to address the requirement for effective BPA detection. The production and composition of α-Fe2O3 nanoparticles were confirmed via rigorous characterization techniques, such as XRD, IR, Raman spectroscopy, XPS, TEM, and UV–Vis spectrophotometry. The nanoparticles showed promising morphology and structure. Then, via electrophoretic deposition, an α-Fe2O3/ITO electrode was created, which showed superior electrochemical qualities for BPA detection. The electrode demonstrated excellent durability and reusability along with great sensitivity (14.4 µA µM−1 cm−2) and a low detection limit (0.03256 µM). The created electrode offers a viable way to quickly and precisely identify BPA in a variety of samples, supporting initiatives related to health, safety, and the environment.

CuxO nanoparticles loaded LTA zeolite as non-enzymatic and noble-metal-free sensing platform for accurate and fast glucose detection

For glucose sensors, improved sensitivity, accuracy, stability and convenience have always been desired. A novel sensing platform combining CuxO (x = 1, 2) nanoparticles and LTA-structured zeolite well fulfills these requirements and achieves breakthrough sensing concentration (6.0 × 10−15 M). In hydrothermal conditions, highly dispersed CuxO nanoparticles are formed and restrined in the nano-opening windows of the zeolite surface pores, ultimately yielding CuxO LTA. These in situ-synthesized CuxO NPs have high catalytic activity, while the zeolite provides a stable and rigid framework. This sensor has good selectivity and sensitivity (1.45 μA μM−1 cm−2) for the determination of glucose under physiological conditions (pH = 7.4) using the DPV method with a limit of detection (LOD) as low as 6.0 × 10−15 M. The amperometry method exhibited a fast response time of only 0.1 s under strong alkaline conditions (1.0 M NaOH) and achieved a sensitivity of 6.94 μA μM−1 cm−2 and LOD of 2.0 × 10−9 M. This advanced hybrid sensor system not only provides a wide range of application environments, but also has important implications for the development of low-cost, stable, fast, and efficient non-enzymatic glucose sensors for noble metals. The theoretical support of density-functional theory (DFT) affirms the interaction between zeolite fine structure and glucose molecules.

Conductive recycled PETg additive manufacturing filament for sterilisable electroanalytical healthcare sensors

Current reports of healthcare sensors within literature that use additive manufacturing electrochemistry all utilise conductive PLA, which is unsuitable for widespread use within the industry. Poly(ethylene terephthalate glycol (PETg) is a polymeric material with proven attributes for additive manufacturing due to its thermal and mechanical properties. Likewise, its excellent chemical stability transforms PETg into a desirable alternative for developing healthcare sensing devices. In this work, we report the production, physicochemical and electrochemical characterisations, as well as the electroanalytical performance of an enhanced electrically conductive additive manufacturing filament made with recycled poly(ethylene terephthalate glycol (rPETg) and a combination of carbon black, multi-walled carbon nanotubes and graphene nanoplatelets as conductive fillers. The post-print activation of additive manufactured electrodes from this material is optimised and shown to produce enhanced electrochemical performance compared to non-activated electrodes, with a k0 of 1.03×10−3 cm s−1. The sterilisation for the real application of sensors in the biomedical field is a critical point, the electrodes were submitted to standard UV light treatment showing to be reliable compared to PLA in the determination of uric acid (30–500 µM) and sodium nitrite (0.1–5 mM) within synthetic urine using differential pulse voltammetry and chronoamperometry techniques. A sensitivity and LOD for uric acid of 25.7 µA µM−1 and 0.27 µM, and 52.6 µA mM−1 and 2.69 µM for nitrite were obtained within synthetic urine, respectively. The re-useability of the electrodes was also tested for the detection of uric acid, showing that the electrode could be used up to 10 times before a significant decrease in the results was observed. We demonstrate that a new conductive rPETg with superior electrochemical performance has a prominent place within the development of additive manufactured-printed healthcare sensors due to its ability to be sterilised and re-used, low solution ingress, and its potential to tackle rising costs and plastic waste problems within the healthcare sector.

CuFe2O4 Nanofiber Incorporated with a Three-Dimensional Graphene Sheet Composite Electrode for Supercapacitor and Electrochemical Sensor Application

The demand for regenerative energy and electric automotive applications has grown in recent decades. Supercapacitors have multiple applications in consumer alternative electronic products due to their excellent energy density, rapid charge/discharge time, and safety. CuFe2O4-incorporated three-dimensional graphene sheet (3DGS) nanocomposites were studied by different characterization studies such as X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The electrochemical studies were based on cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. As prepared, 3DGS/CuFe2O4 nanocomposites exhibited an excellent surface area, high energy storage with appreciable durability, and excellent electrocatalysis properties. A supercapacitor with 3DGS/CuFe2O4-coated nickel foam (NF) electrodes exhibited an excellent specific capacitance of 488.98 Fg−1, a higher current density, as well as a higher power density. After charge–discharge cycles in a 2.0 M KOH aqueous electrolyte solution, the 3DGS/CuFe2O4/NF electrodes exhibited an outstanding cyclic stability of roughly 95% at 10 Ag−1, indicating that the prepared nanocomposites could have the potential for energy storage applications. Moreover, the 3DGS/CuFe2O4 electrode exhibited an excellent electrochemical detection of chloramphenicol with a detection limit of 0.5 µM, linear range of 5–400 µM, and electrode sensitivity of 3.7478 µA µM−1 cm−2.

Double-Cabin Galvanic Cell-Synthesizing Nanoporous, Flower-like, Pb-Containing Pd-Au Nanoparticles for Nonenzymatic Formaldehyde Sensor.

In this work, a novel formaldehyde sensor was constructed based on nanoporous, flower-like, Pb-containing Pd-Au nanoparticles deposited on the cathode in a double-cabin galvanic cell (DCGC) with a Cu plate as the anode, a multiwalled carbon nanotube-modified glassy carbon electrode as the cathode, a 0.1 M HClO4 aqueous solution as the anolyte, and a 3.0 mM PdCl2 + 1.0 mM HAuCl4 + 5.0 mM Pb(ClO4)2 + 0.1 M HClO4 aqueous solution as the catholyte, respectively. Electrochemical studies reveal that the stripping of bulk Cu can induce underpotential deposition (UPD) of Pb during the galvanic replacement reaction (GRR) process, which affects the composition and morphology of Pb-containing Pd-Au nanoparticles. The electrocatalytic activity of Pb-containing nanoparticles toward formaldehyde oxidation was examined in an alkaline solution, and the experimental results showed that formaldehyde mainly caused direct oxidation on the surface of Pb-containing Pd-Au nanoparticles while inhibiting the formation of CO poison to a large degree. The proposed formaldehyde sensor exhibits a linear amperometric response to formaldehyde concentrations from 0.01 mM to 5.0 mM, with a sensitivity of 666 μA mM-1 cm-2, a limit of detection (LOD) of 0.89 μM at triple signal-to-noise, rapid response, high anti-interference ability, and good repeatability.

Bio-synthesized copper nanoparticle anchored ultrathin petal-shaped black phosphorous nanosheets and 3D graphene decorated nanocomposite for electrochemical sensing of methotrexate and paracetamol in diverse matrices

Creating a sensor that can concurrently monitor multiple therapeutic drugs in complex media is a challenging yet essential endeavor. This study presents a novel biomolecule-free electrochemical platform for simultaneous and highly selective detection of methotrexate (MTR) and paracetamol (PRC) in various matrices, including pharmaceutical formulations, simulated blood samples, and water samples. The platform utilizes a multi-layered petal-shaped black phosphorous structure supported on 3D graphene, along with bio-synthesized copper nanoparticles (BP-3DGp@BCuN). Prior to the sensing study, the as-prepared BP-3DGp@BCuN nanocomposite was characterized using FESEM, EDX, FTIR, UV, XPS, Raman spectroscopy, BET, and XRD. Electrochemical studies of BP-3DGp@BCuN nanocomposite reveal a considerable enhancement of the current compared to pure BP or 3DGp. The petal-shaped black phosphorous comprising of 3DGp and BCuN provides a larger surface area, effective mass transport, and more active sites for the attachment of the target analytes that amplified the current signals and detection sensitivity. Furthermore, computational analysis proves that the BP-3DGp@BCuN nanocomposite has strong interaction with the target MTR and PRC compared to other modifiers. Under optimized conditions, the proposed sensing method shows a linear detection range of 0.05–70 µM and 0.5–210 µM with limit of detection (LOD) values of 0.045 nM and 0.36 nM, with high sensitivity of 37.40 and 14.94 μA μM−1 cm−2 for PRC and MTR respectively. The real-life application of the present sensor was examined in pharmaceutical formulations, simulated blood, and water samples.

Fabrication of Mn-TPP/RGO Tailored Glassy Carbon Electrode for Doxorubicin Sensing.

Cancer is a long-standing disease, and the use of anticancer drugs can cause many different harmful side effects. Therefore, the quantitative analysis of anticancer drugs is crucial. Among all the analytical techniques that have been utilized for the detection of doxorubicin, electrochemical sensors have drawn exceptional consideration because they are simple, affordable, and highly sensitive. Manganese tetraphenylporphyrin decorated reduced graphene oxide (Mn-TPP/RGO), tetraphenylporphyrin decorated reduced graphene oxide (TPP/RGO), and reduced graphene oxide (RGO) nanostructure based glassy carbon electrodes (GCEs) were fabricated for the detection of doxorubicin (DOX). The synthesized materials were characterized by FTIR, scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV/vis), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Doxorubicin detection was performed using differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Among the prepared electrodes, Mn-TPP/RGO modified GCE gave an optimum peak current at pH 3. The Mn-TPP/RGO modified electrode showed significant linear response range (0.1-0.6 mM); effective sensitivity (112.09 μA mM-1 cm-2); low detection limit (63.5 μM); and excellent stability, selectivity, repeatability, and reproducibility toward doxorubicin. With differential pulse voltammetry, LoD and sensitivity were 27 μM and 0.174 μA μM-1 cm-2, respectively. Real sample analysis was also performed in human serum, and it depicted reasonable recovery results for spiked doxorubicin.

Multiwalled carbon nanotubes supported Fe nanostructured interfaces for electrochemical detection of uric acid

Uric acid (UA) levels in biological fluids are an important diagnostic and prognostic biomarker for various metabolic disorders. Therefore, a convenient, facile, one-step electroreduction method to develop Fe nanostructured (FeNS) interfaces for highly sensitive electrochemical detection of UA. The synthesis process was thoroughly investigated at various deposition potentials, pH of the electrochemical bath solutions, and growth durations to attain excellent electrochemical response towards UA detection. The morphology and elemental composition of the FeNS/MWCNT were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. We observed uniform deposition of FeNSs with sizes ranging from 100 − 120 nm on tubular nanostructures. The multiwalled carbon nanotubes supported Fe nanostructured interfaces (FeNS/MWCNT) generated at a potential of –1.1 V demonstrated excellent electrochemical response towards UA with a wide linear detection range of 5 to 500 µM with a sensitivity of 6.5605 µA µM−1 cm−2 and low detection limit of 3.26 µM. The excellent electrochemical response was attributed to the synergistic effect of MWCNTs, which facilitated FeNSs growth, leading to increased active sites for electrocatalysis and sensitive detection of UA. The convenience of the synthesis process, tunable electrochemical response, and reliability of the detection process make FeNS interfaces a potential option for developing electrochemical UA sensors.

Single-atom iodine anchored layered graphitic carbon nitride: Dual functional Electrocatalyst for acetaminophen detection and oxygen evolution reaction

Developing highly effective bifunctional electrocatalysts for acetaminophen (ACP) detection and oxygen evolution reaction (OER) is significant and challenging. Thermal decomposition methods were used to create a high-radius and high electronegative iodine doped porous graphitic carbon nitride (IO-gCN) bifunctional electrocatalyst in here. The synergistic effect of pores nature, active sites and nanosheet-like structure, IO-gCN exhibit better ACP detection and OER activity. Under optimized conditions, IO-gCN detection limits (LOD) for ACP is 4.6 nM with a linear range of 0.2–80 μM and sensitivity is 3.234 μA μM−1 cm−2. The proposed nanosheets decorated disposable screen-printed carbon electrode (SPCE) also applied real samples (tap water and human urine sample) to obtained better recovery results. The electrochemical linear sweep voltammetry (LSV) exhibited a lower over potential (270 mV) and small Tafel slope value (144 mV/dec) at 10 mA/cm2 for IO-2 (2 wt% doped gCN) nanosheets under alkaline medium (1 M KOH). Additionally, the chronoamperometry (CA) test and the cyclic voltammetry 3000th cycle test both produced results for long-term stability and hybrid stability. This study offers a straightforward and esoteric method for creating bifunctional electrocatalysts that are free of metal.

Engineering 1T-MoS2 core-shells unified with nitrogen-rich amorphous carbon nanotube for ratiometric low-level detection of nitroquinoline

Nitroquinolines are an important toxic element in ecosystems and have great significance for monitoring the environmental system with appropriate tools for safety assessments. In this work, we developed a sensitive method for accurate and low-level detection of 5-nitroquinoline (5-NQ) using 1T-molybdenum disulfide core shells unified with nitrogen-rich amorphous carbon nanotube (1T-MoS2/NCNT). The 1T-MoS2/NCNT core-shells composite is prepared using a hydrothermal method to fabricate a ratiometric low-level detection of a 5-NQ sensor. The screen-printed carbon electrode (SPCE) modified with 1T-MoS2/NCNT reveals superior electrochemical performance for the detection of 5-NQ with a wide dual linear range of 0.03–258.58 µM and 274.91–604.25 µM, low-level detection limit (LOD) of 0.0089 µM, and a higher sensitivity of 1.83 µA µM−1 cm−2 due to its higher electrochemical active surface area, superior conductivity, and excellent stability. The π-delocalized electrons in 5-NQ facilitate the rapid electron transfer at the electrode-electrolyte interface, allowing easy conjugation with 1T-MoS2/NCNT. The operational stability of the sensor retains 98.7 % after 40 consecutive cycles. In addition, the achieved recovery rates are 96.80–99.76 % and 97.93–99.75 % for 5-NQ detection in various soils and water samples, signifying its feasibility for real-time industrial waste monitoring.

Electrochemically Grown Hole-Rich NiO(OH) Thin Films toward Hole-Mediated Very Fast and Selective Enzyme-Free Electrochemical Sensing of Dopamine under Simulated Environment.

This work aimed to develop an enzyme-free semiconductor-assisted electrochemical technique for the selective detection of the neurotransmitter dopamine. In this case, electrochemically grown nickel oxyhydroxide [NiO(OH)] thin films were chosen to fabricate the sensing platform, i.e., the electrodes. Chronoamperometry was used to deposit the films on indium tin oxide (ITO) coated glass substrates. The films were thoroughly characterized to establish their structure, composition, phase purity, and electrochemical attributes. Electrochemical sensing characteristics were investigated by means of cyclic and differential pulse voltammetry, steady-state amperometry, and electrochemical impedance spectroscopy. The effects of several interfering agents like glucose, sodium chloride, methanol, hydrogen peroxide, and paracetamol were also studied on the detection attributes of dopamine. Significantly high value of sensitivity (11.87 μA μM-1 cm-2) was obtained for dopamine sensing that was associated with a limit of detection (LoD) of 0.22 μM of dopamine. However, the sensitivity (2.51 μA μM-1 cm-2) and LoD (1.20 μM) obtained for serotonin were inferior compared to those of dopamine. The performance of the electrode toward dopamine sensing was not compromised either in the presence of only serotonin or a series of other electroactive interfering agents, which makes the electrode very much dopamine selective. The dopamine response time was 200 ms, which is notably fast. Extensive studies on the effect of temperature, pH and scan rate on the detection of dopamine by the developed electrode material have also been carried out. The developed electrodes were also found to be notably stable for dopamine detection with a decay of only 6.6% in oxidation peak current density after the 50th cycle. Real-life application of the developed electrode material was checked with urine samples from adult male humans and yielded encouraging results.

Soft-Template-Based Manufacturing of Gold Nanostructures for Energy and Sensing Applications.

Implantable and wearable bioelectronic systems can enable tailored therapies for the effective management of long-term diseases, thus minimising the risk of associated complications. In this context, glucose fuel cells hold great promise as in- or on-body energy harvesters for ultra-low-power bioelectronics and as self-powered glucose sensors. We report here the generation of gold nanostructures through a gold electrodeposition method in a soft template for the abiotic electrocatalysis of glucose in glucose fuel cells. Two different types of soft template were used: a lipid cubic phase-based soft template composed of Phytantriol and Brij®-56, and an emulsion-based soft template composed of hexane and sodium dodecyl sulphate (SDS). The resulting gold structures were first characterised by SAXS, SEM and TEM to elucidate their structure, and then their electrocatalytic activity towards glucose was compared in both a three-electrode set-up and in a fuel cell set-up. The Phytantriol/Brij®-56 template led to a nanofeather-like Au structure, while the hexane/SDS template led to a nanocoral-like Au structure. These templated electrodes exhibited similar electrochemical active surface areas (0.446 cm2 with a roughness factor (RF) of 14.2 for Phytantriol/Brij®-56 templated nanostructures and 0.421 cm2 with an RF of 13.4 for hexane/SDS templated nanostructures), and a sensitivity towards glucose of over 7 μA mM-1 cm-2. When tested as the anode of an abiotic glucose fuel cell (in a phosphate-buffered solution with a glucose concentration of 6 mM), a maximum power density of 7 μW cm-2 was reached; however the current density in the case of the fuel cell with the Phytantriol/Brij®-56 templated anode was approximately two times higher, reaching the value of 70 μA cm-2. Overall, this study demonstrates two simple, cost-effective and efficient strategies to manipulate the morphology of gold nanostructures, and thus their catalytic property, paving the way for the successful manufacturing of functional abiotic glucose fuel cells.

Ultrasonically Assembled 0-D Zirconium Oxide on TiO2 Nanorod for a Sensitive Determination of Antibiotic Drug in Biological Samples

Biological, food, and water samples were used to determine the amount of Furazolidone (FUZ) in a variety of applications, including health and nutrition, diagnosis/treatment, pharmacological research, and food/drug quality monitoring. Using hydrothermal and ultrasonication strategies, new type of TiO2 (1D) and ZrO2 (0D) (TiO2/ZrO2) nanocomposites were prepared for FUZ determination. Then the prepared nanocomposite was characterization under X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultra violet visible spectroscopy, and the electrochemical property of the material was characterized by electrochemical impedance spectroscopy and cyclic voltammetry (CV). In addition, detection of FUZ was analyzed by electroanalytical studies such as CV and differential pulse voltammetry (DPV). This proposed TiO2/ZrO2/GCE sensor exhibits excellent electrochemical characteristics, including excellent linearity (0.01–537.22 μM), nanomolar detection limit (19 nM), and encouraging sensitivity (0.35 μA μM−1cm−2) and it shows greater selectivity, repeatability, and longer storage stability. Along with concerned realizability, the primed sensor was analyzed over biological samples that reveal good recovery in real samples.

Fast on-Site and Highly Sensitive Determination of Allura Red Using a Portable Electrochemical Platform Based on Poly(pyrrole) and Bimetallic Nanocomposites Anchored on Reduced Graphene Oxide

Allura red (AR) is classified as an azo dye and is often used as a beverage and food additive. Nevertheless, the need for dose management of Allura red becomes especially important owing to the potential damage caused by the azo structure to the human body and the environment. In order to combat these problems, a novel portable electrochemical platform using a screen-printed carbon electrode (SPCE) that has been modified with poly(pyrrole) and Co-Ni bimetallic nanocomposites anchored on reduced graphene oxide (Co-Ni@rGO) was developed. The purpose of this platform is to enable rapid on-site and very sensitive determination of Allura red from carbonated energy beverages and water samples. Under ideal experimental conditions, the proposed platform’s response exhibits a notable linear relationship with the concentration of Allura red within the range of 0.0001–10 μM, having a very low limit of detection (LOD) of 0.03 nM and a high sensitivity of 24.62 μA μM−1 cm−2. Furthermore, the PPy/Co-Ni@rGO/SPCE platform exhibited favorable characteristics in terms of reproducibility, repeatability, stability, and selectivity for the quantification of Allura red. Consequently, the developed platform was capable of practically and effectively determining the Allura red dye content from various real samples, showing satisfactory recovery rates.

Electrochemical Detection of Nitrofurantoin using Green Synthesized Silver-doped Palladium Nanocluster-Modified Sensor

Aim: This study presents a novel green synthesis approach for successfully fabricating silver-doped palladium nanoclusters (Ag-Pd NCs) using the aqueous leaf extract of Strobilanthes kunthiana as a reducing and stabilizing agent. Background: The environmentally benign method offers a sustainable alternative to conventional chemical synthesis, circumventing hazardous chemicals and minimizing the generation of toxic byproducts. Objectives: The successful green synthesis of Ag-Pd NCs using Strobilanthes kunthiana leaf extract and their application as an efficient electrochemical sensing platform for determining nitrofurantoin (NFT). Methods:: The synthesized Ag-Pd NCs were extensively characterized by using diverse analytical techniques, including UV-Vis spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and cyclic voltammetry (CV). Results: As-synthesized Ag-Pd NCs were employed as a sensing platform for electrochemical detection of NFT, an important antibiotic widely used in clinical applications. The electrochemical method demonstrated a remarkable sensitivity of about 1.56 μA μM−1 cm−2, the lowest detection limit (LOD) of 3.2 μM and a linear range of determination from 5 to 210 μM. This new electrochemical sensor exhibited excellent stability and reproducibility, making it suitable for practical applications in real-world samples. Conclusions: The green synthesis of Ag-Pd NCs using Strobilanthes kunthiana leaf extract and their application as an efficient electrochemical sensing platform for detecting NFT was demonstrated. The combination of green synthesis and advanced electrochemical sensing underscores the potential of these nanomaterials in developing environmentally friendly sensors for pharmaceutical analysis and clinical diagnostics. The findings presented herein will contribute to the growing field of green nanotechnology and sustainable sensor development for advanced healthcare and environmental monitoring.