Sensitive L-leucine sensor based on a glassy carbon electrode modified with SrO nanorods

Crystal plane-integrated strontium oxide/hexagonal boron nitride nanohybrids for rapid electrochemical sensing of anticancer drugs in human blood serum samples

In this work, the crystal plane of strontium oxide (SrO) nanorods was integrated into hexagonal-boron nitride (h-BN) nanosheets to form 1D-2D (SrO/h-BN) composite were utilized for the electrochemical detection of the chemotherapeutic drug 5-fluorouracil (5-Fu). 5-Fu is a clinically proven and the third most frequently applied chemotherapeutic drug for treating solid tumours, such as colorectal, stomach, cutaneous and breast malignancies. Its overdoses lead to toxic metabolite accumulation that has serious adverse consequences on humans, including neurotoxicity, death and the induction of morbidity. Therefore, to improve the chemotherapy and predict the potential adverse effects of 5-Fu residues in the human body, susceptible and quick analytical methods for detecting 5-Fu in human body fluids (blood serum/plasma and urine) are needed. The effective interaction of the synthesized SrO/h-BN composite shows increased efficiency for the electrochemical detection of 5-Fu with good selectivity. Notably, a simple sonochemical method achieved a synergistic interaction between the (100) plane of SrO and the (002) plane of h-BN. Various analytical and spectroscopic techniques were used to characterize the SrO/h-BN nanocomposite, which provided useful insights into the composition and properties of the composite material. The crystalline, structural and chemical characteristics of the as-synthesized material were characterized by XRD, Raman spectroscopy, HR-TEM, XPS and HR-SEM. Furthermore, the proposed electrode's electrochemical sensing capability was analysed using CV, EIS, DPV and i-t curve methods. Numerous active sites created on a modified electrode enhanced the mass transport and electron transfer rate, thereby increasing the electrochemical activity towards the 5-Fu detection. Consequently, under optimized conditions, the SrO/h-BN/GCE exhibited remarkable selectivity, durability, low detection limit (0.003 μM) and wide linear range (0.02-56 μM) for 5-Fu. Finally, the successful application of this sensor for 5-Fu detection in biological samples was successfully tested with high recovery percentages.

Synthesis of strontium oxide-zinc oxide nanocomposites by Co-precipitation method and its application for degradation of malachite green dye under direct sunlight

Photocatalysts workable under direct sunlight are the safe and cost-effective option for water purification. The nanocomposites of strontium oxide and zinc oxide (SZ NCs) were synthesized using coprecipitation method. The respective precursors of SZ NCs were subjected to alkaline hydrolysis and subsequently thermally treated to yield SZ NCs. The SZ NCs with different ZnO composition was synthesized by varying the concentration of ZnO precursor from 0.2 to 1 M. The structural properties of SZ NCs evaluated using X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), and Differential thermal analysis DTA). The optical properties of SZ NCs studied using ultraviolet-visible (UV-Vis) spectroscopic study. The trend observed in the intensity of XRD peaks indicated the occurrence of Zn doping in the crystalline lattice of SrO and the formation of SrO-ZnO composite. Upon incorporation of 1 M of ZnO precursor, the grain size of the SrO was decreased from 49.3 to 27.6 nm. The weight loss in the thermal analysis indicates the removal of carbonates from the sample upon heating and shows the formation of an oxide structure. UV-Vis spectra confirmed that the presence of SrO enhanced the sunlight absorption of SZ NCs. The increase in the composition of ZnO precursors increased the bandgap of SrO (2.09 eV) to the level of ZnO (3.14 eV). SZ NCs exhibited heterostructure morphology, where the nanosized domains with varying shapes (layered and rod-like) were observed. Under direct sunlight conditions, SZ NCs prepared using 1 M/0.6 M of SrO/ZnO precursors exhibited 15-20 % higher photocatalytic efficiency than neat SrO and ZnO. In precise, 1 mg of this SZ NC was degraded 98 % of malachite green dye dissolved in water (10 ppm) under direct sunlight. Additionally, the thermal stability results showed that 18 % decomposition was obtained due to the degradation impurities in SrO/ZnO catalysts and the XRD results revealed that no structural change is obtained in SrO/ZnO photocatalysts after stability test. The SZ NCs can be effectively used as safe and economic sunlight photocatalysts for water purification in remote areas without the electricity.

A fast survey on recent developments in designing colorimetric and fluorescent sensors for the selective detection of essential amino acids

Owing to the biological significance of various amino acids, developing accurate and cost-effective sensing techniques for the selective detection of amino acids has recently attracted growing interest. This review discusses the recent advancements of chemosensors in the selective detection of only essential amino acids out of a total of twenty amino acids, which have been applied in chemosensing research, and the mechanism of their action. The focus is directed towards the detection of the most important essential amino acids, like leucine, threonine, lysine, histidine, tryptophan and methionine, since isoleucine and valine are yet to be explored in regard to chemosensing. According to their chemical and fluorescence properties, different sensing techniques, such as the reaction-based approach, DNA-based sensors, nanoparticle formation, coordination ligand binding, host-guest chemistry, the fluorescence indicator displacement (FID) approach, electrochemical sensors, carbon dot-based sensors, MOF-based sensors and metal-based techniques, have been described.

The synthesis and application of (E)-N'-(benzo[d]dioxol-5-ylmethylene)-4-methyl-benzenesulfonohydrazide for the detection of carcinogenic lead

In this study, noble ligands of (E)-N'-(benzo[d]dioxol-5-ylmethylene)-4-methyl-benzenesulfonohydrazide (BDMMBSH) were prepared via a simple condensation method using benzo-[d][1,3]-dioxole carbaldehyde, benzenesulfonylhydrazine (BSH), and 4-methyl-benzenesulphonylhydrazine (4-MBSH) in good yield, which were crystallized in acetone, EtOAc, and EtOH. The BDMMBSH derivatives were characterized using different spectroscopic techniques, such as 1H-NMR, 13C-NMR, FTIR, and UV-Vis spectroscopy, and their crystal structures were analyzed using the single crystal X-ray diffraction method (SCXRDM). Subsequently, the BDMMBSH compounds were used for the significant detection of the carcinogenic heavy metal ion, lead (Pb2+), via a reliable electrochemical approach. A sensitive and selective Pb2+ sensor was developed via the deposition of a thin layer of BDMMBSH on a GCE with the conducting polymer matrix Nafion (NF). The sensitivity, LOQ, and LOD of the proposed sensor towards Pb2+ were calculated from the calibration curves to be 2220.0 pA μM-1 cm-2, 320.0 mM, and 96.0 pM, respectively. The validation of the BDMMBSH/GCE/NF sensor probe was performed via the selective determination of Pb2+ in spiked natural samples with a satisfactory and rational outcome.

Facile SrO nanorods: an efficient and alternate detection approach for the selective removal of 4-aminophenol towards environmental safety

In this approach, it is introduced a new route to fabricate a reliable and reproducible wet-chemically prepared SrO NRs fabricated glassy carbon electrode sensor probe by electrochemical method for the detection of phenolic derivatives for the safety of environmental and healthcare fields in broad scales.

Detection of 3,4-diaminotoluene based on Sr0.3Pb0.7TiO3/CoFe2O4 core/shell nanocomposite via an electrochemical approach

We reported a scalable sol–gel method for the preparation of Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core–shell magnetic nanocomposite with a finely controlled shell and evaluated its efficiency as an electrochemical sensor for the selective detection of 3,4-diaminotoluene.

Enzyme-free detection of uric acid using hydrothermally prepared CuO·Fe2O3 nanocrystals

Copper oxide doped iron oxide nanocrystals (CuO·Fe₂O₃ NCs) were prepared using a simple hydrothermal technique at low temperature in an alkaline medium.

A non-enzymatic electrochemical approach for l-lactic acid sensor development based on CuO·MWCNT nanocomposites modified with a Nafion matrix

Copper oxide decorated multi-walled carbon nanotube nanocomposites (CuO·MWCNT NCs) were prepared using a simple wet-chemical technique in basic medium.

Simultaneous detection of l-aspartic acid and glycine using wet-chemically prepared Fe3O4@ZnO nanoparticles: real sample analysis

An easy and reliable wet-chemical method was used to synthesize iron oxide doped zinc oxide nanoparticles (Fe₃O₄@ZnO NPs) at a low-temperature under alkaline medium.

Arsenic sensor development based on modification with (E)-N′-(2-nitrobenzylidine)-benzenesulfonohydrazide: a real sample analysis

(E)-N′-(2-Nitrobenzylidene)-benzenesulfonohydrazide was prepared from 2-nitrobenzaldehyde and benzenesulfonylhydrazine by using a condensation method and applied as a selective As³⁺ sensor.

d-Glucose sensor based on ZnO·V2O5 NRs by an enzyme-free electrochemical approach

A simple wet-chemical technique was used to prepare zinc oxide-doped vanadium pentaoxide nanorods (ZnO·V₂O₅ NRs) in an alkaline environment. The synthesized ZnO·V₂O₅ NRs were characterized using typical methods, including UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The d-glucose (d-GLC) sensor was fabricated with modification of a slight coating of nanorods (NRs) onto a flat glassy carbon electrode (GCE). The analytical performances, such as the sensitivity, limit of quantification (LOQ), limit of detection (LOD), linear dynamic range (LDR), and durability, of the proposed d-GLC sensor were acquired by a dependable current–voltage (I–V) process. A calibration curve of the GCE/ZnO·V₂O₅ NRs/Nf sensor was plotted at +1.0 V over a broad range of d-GLC concentrations (100.0 pM–100.0 mM) and found to be linear (R² = 0.6974). The sensitivity (1.27 × 10⁻³ μA μM⁻¹ cm⁻²), LOQ (417.5 mM), and LOD (125 250 μM) were calculated from the calibration curve. The LDR (1.0 μM–1000 μM) was derived from the calibration plot and was also found to be linear (R² = 0.9492). The preparation of ZnO·V₂O₅ NRs by a wet-chemical technique is a good advancement for the expansion of nanomaterial-based sensors to support enzyme-free sensing of biomolecules in healthcare fields. This fabricated GCE/ZnO·V₂O₅ NRs/Nf sensor was used for the recognition of d-glucose in real samples (apple juice, human serum, and urine) and returned satisfactory and rational outcomes.

A simple wet-chemical technique was used to prepare zinc oxide-doped vanadium pentaoxide nanorods (ZnO·V₂O₅ NRs) in an alkaline environment.

Fabrication of a Ga3+ sensor probe based on methoxybenzylidenebenzenesulfonohydrazide (MBBSH) by an electrochemical approach

A thin-layer of (E)-N′-methoxybenzylidenebenzenesulfonohydrazide (MBBSH) was fabricated by the deposition of MBBSH onto a smooth glassy carbon electrode with nafion binder for the sensitive and selective Ga³⁺ sensor probe.

A Ce2+ sensor based on napthalen-1-yl-methylene-benzenesulfonohydrazide (NMBSH) molecules: ecological sample analysis

A sensitive and selective Ce²⁺ sensor was developed based on napthalen-1-yl-methylene-benzenesulfonohydrazide (NMBSH) derivatives via an electrochemical approach.

Fabrication of 3-methoxyphenol sensor based on Fe3O4 decorated carbon nanotube nanocomposites for environmental safety: Real sample analyses

Iron oxide ornamented carbon nanotube nanocomposites (Fe3O4.CNT NCs) were prepared by a wet-chemical process in basic means. The optical, morphological, and structural characterizations of Fe3O4.CNT NCs were performed using FTIR, UV/Vis., FESEM, TEM; XEDS, XPS, and XRD respectively. Flat GCE had been fabricated with a thin-layer of NCs using a coating binding agent. It was performed for the chemical sensor development by a dependable I-V technique. Among all interfering analytes, 3-methoxyphenol (3-MP) was selective towards the fabricated sensor. Increased electrochemical performances for example elevated sensitivity, linear dynamic range (LDR) and continuing steadiness towards selective 3-MP had been observed with chemical sensor. The calibration graph found linear (R2 = 0.9340) in a wide range of 3-MP concentration (90.0 pM ~ 90.0 mM). The limit of detection and sensitivity were considered as 1.0 pM and 9×10-4 μAμM-1cm-2 respectively. The prepared of Fe3O4.CNT NCs by a wet-chemical progression is an interesting route for the development of hazardous phenolic sensor based on nanocomposite materials. It is also recommended that 3-MP sensor is exhibited a promising performances based on Fe3O4.CNT NCs by a facile I-V method for the significant applications of toxic chemicals for the safety of environmental and health-care fields.

Ultrasensitive and label-free detection of creatine based on CdO nanoparticles: a real sample approach

Low-dimensional cadmium oxide nanoparticles (CdO NPs) were prepared by a facile wet-chemical method, which later electrochemically investigated for the determination of selective creatine and measured the analytical sensor parameters such as sensitivity, limit of detection (LOD), linear dynamic range (LDR), long-term stability, and real-sample validation.

A glassy carbon electrode modified with γ-Ce2S3-decorated CNT nanocomposites for uric acid sensor development: a real sample analysis

γ-Ce₂S₃-decorated multi-walled carbon nanotube nanocomposite (Ce₂S₃-CNT NC) was synthesized by a wet chemical method in basic media.