In Situ Electrochemical Cobalt Doping in Perovskite-Structured Lanthanum Nickelate Thin Film Toward Energy Conversion Enhancement of Polymer Solar Cells.

This study demonstrates that the electrochemical doping of lanthanum nickelate (LNO) with cobalt ions is a promising strategy for enhancing its physical and electrochemical properties, which are critical for energy storage and conversion devices. LNO emerges as a promising hole transport layer (HTL) in solar cells due to its stability, large band gap, and high transparency. Nevertheless, its low conductivity and improperly aligned band positions are persistent problems. Here, in a pioneering endeavor, Co-doped LNO thin films were synthesized electrochemically and applied as the HTL in polymer solar cells (PSCs). Characterization revealed the impact of Co doping on the electrochemical, structural, morphological, and optical properties of LNO thin films. Depending on the Co doping level, PSCs based on 10 mol % Co-doped LNO outperformed pure LNO, achieving a champion efficiency of 6.11% with enhanced short-circuit current density (12.84 mA cm-2), fill factor (68%), open-circuit voltage (0.70 V), and external quantum efficiency (82.6%). This enhancement resulted from decreased series resistance, refined surface morphology, minimized trap-assisted recombination, enhanced conductivity, increased charge carrier production, favorable energy level alignment, and improved current extraction facilitated by LNC0.10O HTL. Moreover, the unencapsulated PSC-LNC0.10O long-term stability notably improved and retained 86% of its initial PCE after 450 h storage in ambient air, 82% after being continuously heated to 85 °C for 300 h, and 80% after operating at maximum power point for 300 h. These findings offer a straightforward approach to enhancing PSC performance through Co doping of LNO, supported by density functional theory (DFT) calculations that validate the experimental results and confirm the improvement in optical properties and stability of PSCs as an HTL.

An antifouling impedimetric sensor based on zinc oxide embedded polyvinyl alcohol nanoplatelets for wide range dopamine determination in the presence of high concentration ascorbic acid.

Dopamine determination is of great importance for the early diagnosis of neurological diseases. However, dopamine sensors mostly encounter important challenges such as surface fouling and interference of co-existing biochemicals. Here, nanoplatelets of zinc oxide embedded polyvinyl alcohol (NP-ZnO/PVA) were utilized for providing an efficient fouling-free surface for selective dopamine determination in concentrations as high as 3 mM of dopamine in the presence of ascorbic acid interference. The fouling-free properties was provided mainly by pH-inducibility of the NP-ZnO/PVA nanocomposite at the rationally adjusted sensing conditions. ZnO plays a vital role in the electrocatalytic oxidation of dopamine, and PVA provides surface functional groups that minimize the surface interactions with interferences or fouling agents. The NP-ZnO/PVA nanocomposite fabrication process was performed by PVA assisted ZnO electro-synthesis onto the surface of fluorine-doped tin oxide (FTO) conducting glass. The fabricated FTO/NP-ZnO/PVA sensor was characterized utilizing FE-SEM, EDX, XRD, TGA-DTG, BET-BJH and FTIR techniques. Impedimetric determination of dopamine was performed in the wide linear range from 20.0 nM to 3.0 mM with a low detection limit of 5.0 nM. The applicability of FTO/NP-ZnO/PVA for dopamine determination was successfully tested in real samples. The NP-ZnO/PVA provides a great prospective to be an efficacious material for the construction of dopamine electrochemical sensing platforms.

Simultaneous reduction and adsorption of arsenite anions by green synthesis of iron nanoparticles using pomegranate peel extract.

PURPOSE: Arsenic is a toxic metalloid that is present in the environment as arsenate and arsenite anions. Exposure to arsenic anions caused skin problems, degenerative diseases, kidney, liver, and lung cancer. The synthesized iron nanoparticles (NPs) were examined as a green low-cost adsorbent for the removal of arsenite anions from aqueous solution via batch adsorption procedure. METHODS: Iron NPs were prepared in a single step by the reaction of Fe+3 0.01 M solution with a fresh aqueous solution of 2% w/v pomegranate peel extract (PPE) as both reducing and capping agents. The physicochemical properties of peel were investigated by some experiments and functional groups were determined by the FT-IR spectrum. The electrochemical behavior of PPE was studied using cyclic voltammetry on a glassy carbon electrode as produced a cathodic peak at range 120-400 mV. The progress of nZVI production was monitored by a decrease of 372 nm wavelength UV-Vis spectra of PPE. The 27 adsorption experiments were carried out as a function of solution pH, initial arsenite concentration, mass adsorbent, and contact time according to DOE. RESULTS: The rapid rate of adsorption was observed at 20-60 min, indicating that the principal mechanism dominating the sorption process was reduction and chemical adsorption. The arsenite removal efficiency was found to be dependent on the solution pH, adsorbent dose, and initial concentration, respectively. CONCLUSION: The experimental data show the ability of the synthesized iron NPs to remove arsenate from solution in both synthetic and polluted natural water. The thermodynamic study suggested the spontaneous and endothermic nature of adsorption of arsenite by green synthesized iron NPs. The iron NPs synthesized with PPE increased the removal of arsenite with an increase in the active surface, indicating some chemical interactions between the adsorbent and oxoanions.

Polyvinyl alcohol as a crucial omissible polymer to fabricate an impedimetric glucose biosensor based on hierarchical 3D-NPZnO/chitosan.

Highly stable and reliable monitoring of glucose is of great importance for diabetes patients. This paper describes the application of two types of polymer for developing a reliable impedimetric glucose biosensor by designing an efficient nanoporous microenvironment for enzyme loading. Polyvinyl alcohol (PVA) was used as a sacrifice polymer to prepare a uniform 3D-nanoporous ZnO (3D-NPZnO) platform through electrodeposition of ZnO/PVA layer followed by PVA elimination via annealing. The carbohydrate polymer, chitosan (CTS), with a high isoelectric point (pI = 7.0-9.0), was selected in accompanying with 3D-NPZnO (pI = 9.5) to provide a hierarchical 3D-NPZnO/CTS microenvironment of a favorable isoelectric point for glucose oxidase enzyme (pI = 4.2) loading. The characterization of structural features and monitoring of the biosensor fabrication process was performed using FE-SEM, EDX, TGA-DTG, FTIR, UV-Vis, BET-BJH, XRD, CV, and EIS techniques. The fabricated platform, which shows a wide linear range of 1.0-18.0 mM and a low detection limit of 0.2 mM for glucose determination, was successfully used for real sample analysis. The proposed fabrication method can be applied for immobilizing the other low isoelectric point enzymes and biomolecules.

A DNA Based Biosensor Amplified With ZIF-8/Ionic Liquid Composite for Determination of Mitoxantrone Anticancer Drug: An Experimental/Docking Investigation.

An ultrasensitive DNA electrochemical biosensor based on the carbon paste electrode (CPE) amplified with ZIF-8 and 1-butyl-3-methylimidazolium methanesulfonate (BMIMS) was fabricated in this research. The DNA/BMIMS/ZIF-8/CPE was used for the selective determination of a mitoxantrone anticancer drug in aqueous solution, resulting in a good catalytic effect and a powerful ability for determining mitoxantrone. Also, the interaction of the mitoxantrone anticancer drug with guanine bases of ds-DNA was used as a powerful strategy in the suggested biosensor, which was confirmed with docking investigation. Docking study of mitoxantrone into the ds-DNA sequence showed the intercalative binding mode of mitoxantrone into the nitrogenous-based pairs of ds-DNA. The effective factors such as ds-DNA concentration, temperature, buffer types, and incubation time were also optimized for the fabricated mitoxantrone biosensor. The results showed that, under optimum conditions (T = 25°C; incubation time=12 min; pH= 4.8 acetate buffer solution and [DNA] = 50 mg/L), the DNA/BMIMS/ZIF-8/CPE could be used in mitoxantrone assay in a concentration ranging from 8.0 nM to 110 µM with a detection limit of 3.0 nM. In addition, recovery data between 99.18 and 102.08% were obtained for the determination of mitoxantrone in the injection samples using DNA/ZIF-8/BMIMF/CPE as powerful biosensors.

Evaluation of Pt,Pd-Doped, NiO-Decorated, Single-Wall Carbon Nanotube-Ionic Liquid Carbon Paste Chemically Modified Electrode: An Ultrasensitive Anticancer Drug Sensor for the Determination of Daunorubicin in the Presence of Tamoxifen.

Measuring the concentration of anticancer drugs in pharmacological and biological samples is a very useful solution to investigate the effectiveness of these drugs in the chemotherapy process. A Pt,Pd-doped, NiO-decorated SWCNTs (Pt,Pd-NiO/SWCNTs) nanocomposite was synthesized using a one-pot procedure and combining chemical precipitation and ultrasonic sonochemical methods and subsequently characterized by TEM and EDS analysis methods. The analyses results showed the high purity and good distribution of elements and the ~10-nm diameter of the Pt,Pd-NiO nanoparticle decorated on the surface of the SWCNTs with a diameter of about 20-30 nm. Using a combination of Pt,Pd-NiO/SWCNTs and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (1B23DTFB) in a carbon paste (CP) matrix, Pt,Pd-NiO/SWCNTs/1B23DTFB/CP was fabricated as a highly sensitive analytical tool for the electrochemical determination of daunorubicin in the concentration range of 0.008-350 µM with a detection limit of 3.0 nM. Compared to unmodified CP electrodes, the electro-oxidation process of daunorubicin has undergone significant improvements in current (about 9.8 times increasing in current) and potential (about 110 mV) decreasing in potential). It is noteworthy that the designed sensor can well measure daunorubicin in the presence of tamoxifen (two breast anticancer drugs with a ΔE = 315 mV. According to the real sample analysis data, the Pt,Pd-NiO/SWCNTs/1B23DTFB/CP has proved to be a promising methodology for the analysis and measuring of daunorubicin and tamoxifen in real (e.g., pharmaceutical) samples.

Glucose Oxidase/Nano-ZnO/Thin Film Deposit FTO as an Innovative Clinical Transducer: A Sensitive Glucose Biosensor.

In the present research, a new biocompatible electrode is proposed as a rapid and direct glucose biosensing technique that improves on the deficiencies of fast clinical devices in laboratory investigations. Nano-ZnO (nanostructured zinc oxide) was sputtered by reactive direct current magnetron sputtering system on a precovered fluorinated tin oxide (FTO) conductive layer. Spin-coated polyvinyl alcohol (PVA) at optimized instrumental deposition conditions was applied to prepare the effective medium for glucose oxidase enzyme (GOx) covalent immobilization through cyanuric chloride (GOx/nano-ZnO/PVA/FTO). The electrochemical behavior of glucose on the fabricated GOx/nano-ZnO/PVA/FTO biosensor was investigated by I-V techniques. In addition, field emission scanning electron microscopy and electrochemical impedance spectroscopy were applied to assess the morphology of the modified electrode surface. The I-V results indicated good sensitivity for glucose detection (0.041 mA per mM) within 0.2-20 mM and the limit of detection was 2.0 µM. We believe that such biodevices have good potential for tracing a number of biocompounds in biological fluids along with excellent accuracy, selectivity, and precise analysis. The fast response time of the fabricated GOx/nano-ZnO/PVA/FTO biosensor (less than 3 s) could allow most types of real-time analysis.

Controllable Pulse Reverse Electrodeposition of Mesoporous Li xMnO2 Nano/Microstructures with Enhanced Electrochemical Performance for Li-Ion Storage.

Given the ever-growing demand of electric vehicles and renewable energies, addressing the poor cyclic stability of lithium manganese dioxide is an urgent challenge. In this study, pulse reverse current as the driving force of a one-pot anodic electrodeposition was exploited to design the physicochemical and electrochemical characteristics of lithium manganese dioxides as cathode materials of Li-ion battery. The pulse reverse parameters, including the span of anodic and cathodic current application ( ta and tc) and frequency ( f'), were systematically modulated to determine the optimized values through monitoring the physicochemical properties using X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, Raman spectroscopy, N2 adsorption-desorption isotherms, and inductively coupled plasma-optical emission spectroscopy, as well as the electrochemical properties using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge at different currents. Based on the results, Li0.65MnO2 synthesized using ta = 95 ms, tc = 5 ms, and f' = 8.33 Hz at the constant magnitude of anodic peak current density of 1 mA dm-2 was determined as the optimized sample. The optimized lithium manganese dioxide rendered superior electrochemical performance with the initial discharge capacity of 283 mAh g-1, which accounts for 96.4% of the theoretical discharge capacity, preserving 88.3% of this capacity after 300 cycles at 0.1 C and, in the meantime, was able to release a discharge capacity of 115 mAh g-1 even after cycling at a higher current of 10 C. The superior electrochemical behavior of Li0.65MnO2 was attributed to the exclusive hierarchical urchin-like morphology as well as mesoporous nano/microstructures having a notably high Brunauer-Emmett-Teller surface area of 320.12 m2 g-1 alongside mixed-phase α/γ structure owing to the larger 2 × 2 tunnels, which offer more facile Li+ diffusion.

A novel impedimetric glucose biosensor based on immobilized glucose oxidase on a CuO-Chitosan nanobiocomposite modified FTO electrode.

This research aims at elaborating on the construction of a novel nanostructured copper oxide (Nano-CuO) sputtered thin film on the conductive fluorinated-tin oxide (FTO) layer that was exploited to immobilize glucose oxidase (GOx) enzyme via chitosan for developing impedimetric glucose biosensing. The distinct Nano-CuO thin film was fabricated by reactive DC magnetron sputtering system at the optimized instrumental deposition conditions. The FTO/Nano-CuO/Chitosan/GOx biosensor containing several layers afforded excellent microenvironment for rapid biocatalytic reaction to glucose. Field emission-scanning electron microscopy (FE-SEM), Ultraviolet-Visible spectroscopy (UV-Vis), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were established the morphology of modified electrode's surface and electrochemical behavior of glucose on the fabricated biosensor. Characterization of the surface morphology and roughness of CuO thin film by FE-SEM exhibits cavities of the nanoporous film as an effective biosensing area for covalent enzyme immobilization. Invented FTO/Nano-CuO/Chitosan/GOx biosensor was employed for glucose determination using the impedimetric technique. The impedimetric outcomes display high sensitivity for glucose (0.261 kΩ per mM) detection within 0.2-15 mM and limit of detection as 27 µM. The declared biosensor has been applied as a careful, noncomplicated, and exact biosensor for recognition of glucose in the real samples analysis.

Modification of pomegranate waste with iron ions a green composite for removal of Pb from aqueous solution: equilibrium, thermodynamic and kinetic studies.

Pomegranate waste modified with Fe2+ and Fe3+ ions followed with carbonization were used as an adsorbent to remove the Pb2+ ions from aqueous solution. To optimum the highest adsorption efficiency, adsorption experiments were conducted on iron modified carbons by batch technique. The characteristic of composite was studied by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). The best pH for control of chemical adsorption was selected within pH of 6.0-6.5. It was observed that the contact time of 90 min, initial concentration 50.0 ppm, and adsorbent dose, 1.0 g/100 ml solution was found to be optimum conditions. On this condition, the maximum adsorption capacity was obtained 27.5 and 22.5 mg/g for Fe2+ and Fe3+ impregnated pomegranate peel carbons (PPC), respectively. The value of Cid, 1.584 for Fe2+-PPC and 0.552 for Fe3+-PPC, indicates that the effect of the boundary layer is more important in adsorption of Pb2+ by Fe2+-PPC and the pore diffusion is the rate limiting mechanism after 30 min. Thermodynamic parameters of Gibbs free energy, enthalpy, and entropy of Pb2+ adsorption on iron-modified carbons suggest that the adsorption process is favorable and spontaneous under the optimum condition.

Solid-phase microextraction of ultra-trace amounts of tramadol from human urine by using a carbon nanotube/flower-shaped zinc oxide hollow fiber.

A new method is successfully developed for the separation and determination of a very low amount of tramadol in urine using functionalized multiwalled carbon nanotubes/flower-shaped zinc oxide before solid-phase microextraction combined with gas chromatography. Under ultrasonic agitation, a sol of multiwalled carbon nanotubes and flower-shaped zinc oxide were forced into and trapped within the pore structure of the polypropylene and the sol solution immobilized into the hollow fiber. Flower-shaped zinc oxide was synthesized and characterized by Fourier transform infrared spectroscopy. The morphology of the fabricated solid-phase microextraction surface was investigated by scanning electron microscopy and X-ray diffraction. The parameters affecting the extraction efficiencies were investigated and optimized. Under the optimized conditions, the method shows linearity in a wide range of 0.12-7680 ng/mL, and a low detection limit (S/N = 3) of 0.03 ng/mL. The precision of the method was determined and a relative standard deviation of 3.87% was obtained. This method was successfully applied for the separation and determination of tramadol in urine samples. The relative recovery percentage obtained for the spiked urine sample at 1000 ng/mL was 94.2%.

Disposable urea biosensor based on nanoporous ZnO film fabricated from omissible polymeric substrate.

In the present study, a facile and simple fabrication method of a semiconductor based urea biosensor was reported via three steps: (i) producing a ZnO-PVA composite film by means of a polymer assisted electrodeposition of zinc oxide (ZnO) on the F-doped SnO2 conducting glass (FTO) using water soluble polyvinyl alcohol (PVA), (ii) obtaining a nanoporous ZnO film by PVA omission via a subsequent post-treatment by annealing of the ZnO-PVA film, and (iii) preparation of a FTO/ZnO/Urs biosensor by exploiting a nanoporous ZnO film as an efficient and excellent platform area for electrostatic immobilization of urease enzyme (Urs) which was forced by the difference in their isoelectric point (IEP). The characterization techniques focused on the analysis of the ZnO-PVA film surfaces before and after annealing, which had a prominent effect on the porosity of the prepared ZnO film. The surface characterization of the nanostructured ZnO film by a field emission-scanning electron microscopy (FE-SEM), exhibited a film surface area as an effective bio-sensing matrix for enzyme immobilization. The structural characterization and monitoring of the biosensor fabrication was performed using UV-Vis, Fourier Transform Infrared (FT-IR), Raman Spectroscopy, Thermogravimetric Analysis (TGA), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) techniques. The impedimetric results of the FTO/ZnO/Urs biosensor showed a high sensitivity for urea detection within 8.0-110.0mg dL(-1) with the limit of detection as 5.0mg dL(-1).

Photoelectric characterization of fabricated dye-sensitized solar cell using dye extracted from red Siahkooti fruit as natural sensitizer.

Natural dye extracted from Siahkooti fruit with/without purification by solid phase extraction (SPE) technique was used in the fabrication of DSSC as natural sensitizer. The UV-Vis absorption spectroscopy and Fourier transform infrared (FTIR) were employed to indicate the presence of anthocyanins in the fruit of red Siahkooti. The photoelectrochemical performance and the efficiency of assembled DSSC using Siahkooti fruit dye extract were evaluated and efficiency enhancement was obtained by a preliminary purification of extracted dye. The efficiency and fill factor of the DSSC using purified Siahkooti fruit dye were 0.32% and 0.73%, respectively. The results successfully showed that the DSSC, using Siahkooti fruit extract as a dye sensitizer, is useful for the preparation of environmentally friendly, low-cost, renewable and clean sources of energy.