An Ultrasensitive Electrochemical Sensor Using Banana Peel Activated Carbon/NiFe2O4/MnCoFe-LDH Nanocomposites for Anticancer Drug Determination.

In the current study, we report the synthesis of a novel composite material composed of banana peel activated carbon (BPAC), nickel iron oxide (NiFe2O4), and manganese cobalt iron layered double hydroxide (MnCoFe-LDH) to create a high-performance electrochemical sensor to detect Palbociclib (PLB). The composite was successfully immobilized on a glassy carbon electrode (GCE) surface to create a modified electrode. The performance of the electrode was thoroughly evaluated, considering parameters such as electroactive surface areas (ESA), electron transfer rate constant (k0), and exchange current density (j0). The developed BPAC/NiFe2O4/MnCoFe-LDH/GCE exhibited a wide linear dynamic range of 0.01-13.0 µM for PLB concentration, accompanied by a detection limit at a low level (3.5 nM). Furthermore, it can be applied to the determination of PLB in human urine and pharmaceutical samples with excellent recoveries (98.5-102.9%) and RSD values lower than 3%, establishing its potential for precise PLB determination in pharmaceutical and biological samples. This research contributes to the advancement of electrochemical sensor technology for the detection of important anticancer drugs in real-world applications.

Magnetic Rubber@Ni-Co layered double hydroxide derived from ZIF-67 template as nanostructured sorbent; application in determination of anticancer drugs in plasma samples.

In this study, a magnetic three-dimensional nano-composite based on Rubber-Fe3O4@Ni-Co Layered double hydroxide derived from ZIF-67 template was synthesized by a hydrothermal method. The proposed nano-composite was used as a sorbent for the enrichment of trace amounts of anti-cancer drugs (dasatinib and erlotinib hydrochloride) from plasma samples followed by determination using high-performance liquid chromatographic analysis (HPLC-UV). The synthesized nano-sorbent was characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating-sample magnetometer, Brunauer-Emmett-Teller surface analysis, Barrett-Joyner-Halenda pore size analysis and energy dispersive X-ray spectroscopy. Under optimal experimental conditions, factors affecting on extraction efficiency such as pH, ionic strength, extraction temperature and time, desorption solvent and time, the limit of detection (LODs) and the limit of quantification (LOQs) were obtained as 0.6, 2 µg/L for both of dasatinib and erlotinib, respectively. Also, linear range of the method were 2-500 and 2-1000 µg/L for dasatinib and erlotinib, respectively. Relative standard deviations (RSD%) for the repeatability of extraction on sorbent to sorbent were obtained as 3.59, 1.97 %, and one sorbent reusability were investigated and relative standard deviation values were obtained 5.35, 3.30 % for dasatinib and erlotinib, respectively.

Electrochemical Detection of Melphalan in Biological Fluids Using a g-C3N4@ND-COOH@MoSe2 Modified Electrode Complemented by Molecular Docking Studies with Cellular Tumor Antigen P53.

Melphalan (Mel) is a potent alkylating agent utilized in chemotherapy treatments for a diverse range of malignancies. The need for its accurate and timely detection in pharmaceutical preparations and biological samples is paramount to ensure optimized therapeutic efficacy and to monitor treatment progression. To address this critical need, our study introduced a cutting-edge electrochemical sensor. This device boasts a uniquely modified electrode crafted from graphitic carbon nitride (g-C3N4), decorated with activated nanodiamonds (ND-COOH) and molybdenum diselenide (MoSe2), and specifically designed to detect Mel with unparalleled precision. Our rigorous testing employed advanced techniques such as cyclic voltammetry and differential pulse voltammetry. The outcomes were promising; the sensor consistently exhibited a linear response in the range of 0.5 to 12.5 µM. Even more impressively, the detection threshold was as low as 0.03 µM, highlighting its sensitivity. To further enhance our understanding of Mel's biological interactions, we turned to molecular docking studies. These studies primarily focused on Mel's interaction dynamics with the cellular tumor antigen P53, revealing a binding affinity of -5.0 kcal/mol. A fascinating observation was made when Mel was covalently conjugated with nanodiamond-COOH (ND-COOH). This conjugation resulted in a binding affinity that surged to -10.9 kcal/mol, clearly underscoring our sensor's superior detection capabilities. This observation also reinforced the wisdom behind incorporating ND-COOH in our electrode design. In conclusion, our sensor not only stands out in terms of sensitivity but also excels in selectivity and accuracy. By bridging electrochemical sensing with computational insights, our study illuminates Mel's intricate behavior, driving advancements in sensor technology and potentially revolutionizing cancer therapeutic strategies.

The usability of green deep eutectic solvents in hollow fiber Liquid-Phase microextraction for the simultaneous extraction of analytes of different Natures: A comprehensive study.

In the current study, a wide range of deep eutectic solvents (DESs) with different properties (hydrophilic, hydrophobic, ionic, and nonionic) were prepared in the initial phase. Subsequently, an assessment was conducted to evaluate some characteristics of the produced DESs, including their stability at room temperature and their capacity to extract three distinct types of analytes (anionic, cationic, and non-ionic) simultaneously through hollow fiber-liquid phase microextraction (HF-LPME) technique. To carry out the extraction procedure, the prepared DESs were inserted into the pores (as supported liquid membrane (SLM)) and lumen of hollow fiber membrane (HF) to apply two-phase and three-phase HF-LPME techniques. After a thorough evaluation, the three-phase HF-LPME technique (HF(3)-LPME) was chosen by using a mixture of menthol/TBAB-based hydrophobic DES (DES-35) as SLM and the mixture of malic acid/citric acid/water-based hydrophilic DES (DES-2) as an extraction solvent in the lumen of HF. All factors affecting the extraction recovery (including pH, extraction time, extraction temperature, stirring speed, and salt effect) were optimized utilizing the one-variable-at-a-time (OVAT) methodology. After applying the extraction procedure, all extracted samples were analyzed using the UV-Vis spectrometer and results were recorded at different wavelengths including 655 nm for Methylene blue, 550 nm for Amaranth, and 375 nm for Quercetin. The calibration graphs showed linearity in the range of 20.0-1500 µg/L, with a limit of detection of 6.2-15.1 µg/L and correlation coefficients higher than 0.9913 for the studied analytes. Moreover, the intra-day RSD, inter-day RSD, preconcentration factor (PF), enrichment factors (EF), and extraction recoveries (ER%) were obtained in the range of 3.1-4.8, 3.8-6.7, 125, 102.9-111.4, and 82.3-89.1 %, respectively. The use of the selected DES in the HF-LPME methodology resulted in an ecologically friendly strategy, as evidenced by the use of green metrics from the SPMS tool. The proposed strategy is also considered environmentally friendly due to its use of minimal solvents, waste reduction, and low energy consumption. The proposed technique effectively and simultaneously extractedmethylene blue, amaranth, and quercetin analytes in different real samples.

Dispersive micro-solid phase extraction (D-µSPE) of nickel on activated nanodiamonds@Bi2WO6 nanocomposite from water and food samples.

This study presents an original nano-sorbent using activated nanodiamonds@Bi2WO6 to separate and enrich nickel ions from water and food samples. FTIR, XRD, FE-SEM, FE-SEM-EDX, EDS-TEAM, TGA, and BET were used to characterize the nanocomposite. It has a large surface area, active functional groups, and better reactivity. Ni(II) ions were determined as Ni(II)-PADAP chelates using UV-VIS spectroscopy. The parameters were studied and optimized, including pH (6), eluent type and volume (1 mL), ligand quantity (10 µg), sorbent dosage (20 mg), and contact time (1 min). The method has a low limit of detection (LOD) of 1.6 µg L-1, a limit of quantification (LOQ) of 5.3 µg L-1, a relative standard deviation of 4.5%, and a preconcentration factor of 10. The method was validated by applying to certified reference materials (BCR estuarine water 505 and 1573a NIST). The method was successfully applied to tap waters, industrial waste waters, and vegetables.

Carboxylated nanodiamonds@CuAl2O4@TiO2 nanocomposite for the dispersive micro-solid phase extraction of nickel at trace levels from food samples.

Heavy metal pollution poses a significant health risk, necessitating regular environmental monitoring for public safety. Elevated nickel concentrations can disrupt ecosystems and impact human health. This study presents a nano-sorbent can be used for dispersive micro-solid phase extraction of nickel. The nano-sorbent was characterized using FT-IR, XRD, FESEM, BET, and BJH. It demonstrated remarkable efficiency due to its nanoscale properties, optimizing results in exceptional extraction performance with minimal interference from common ions. A flame atomic absorption spectrometer was utilized for all measurements. It has a low LOD (0.29 µg L-1) and RSDs% (7.3 % and 6 % intra-day and inter-day, respectively), minimal variation, and a precisely accurate correlation (0.997). It can be used on black tea, green tea, carrots, coffee beans, tuna fish, herring fish, tobacco, soil, natural water, and wastewater samples. The accuracy of the method was assessed by analyzing TMDA-64.3 fortified water and NIST 1573a tomato leaves certified reference materials.

Micro solid phase extraction of lead and cadmium using functionalized nanodiamonds@CuAl2O4@HKUST-1 nanocomposite for FAAS analysis in food and water samples.

This study focuses on the development and application of a novel nanocomposite (functionalized nanodiamonds@CuAl2O4@HKUST-1)-based µ-SPE method for the sensitive and selective extraction of Pb and Cd from food and water samples. The technique offers high sensitivity and selectivity, allowing accurate measurement of these metals at trace levels. The detection limit is 0.031 µg kg-1 for Cd and 0.052 µg kg-1 for Pb, with a relative standard deviation of 1.7 % for Cd and 4.8 % for Pb. The method was successfully applied to real samples and efficiently quantified Pb and Cd in food and natural water samples. The highest concentrations were found in red lentils (0.274 µg kg-1 Pb) and fresh mint (0.197 µg kg-1Cd), but still below recommended limits set by FAO/WHO (300 µg kg-1 for Pb and 200 µg kg-1 for Cd). It promises to ensure food safety, monitor environmental contamination, and informs regulatory decisions to protect public health.

Novel extracellular synthesized silver nanoparticles using thermophilic Anoxybacillus flavithermus and Geobacillus stearothermophilus and their evaluation as nanodrugs.

In this investigation, two new thermophilic bacteria were isolated. The new isolates were characterized by 16S rRNA, biochemical, morphological, and physiological analyzes and the isolates were identified as Geobacillus stearothermophilus strain Gecek20 and thermophilic Anoxybacillus flavithermus strain Gecek19. Various biological activities of extracellular Ag-NPs synthesized from thermophilic G. stearothermophilus strain Gecek20 and thermophilic A. flavithermus strain Gecek19 were evaluated. The produced NPs were analyzed by SEM, SEM-EDX, and XRD analyses. The antioxidant abilities of new synthesized Ag-NPs from thermophilic G. stearothermophilus strain Gecek20 (T1-Ag-NPs) and new synthesized Ag-NPs from thermophilic A. flavithermus strain Gecek19 (T2-Ag-NPs) were studied by DPPH inhibition and metal chelating ability. The highest DPPH and metal chelating abilities of T1-Ag-NPs and T2-Ag-NPs at 200 mg/L concentration were 93.17 and 90.85%, and 75.80 and 83.64%, respectively. The extracellular green synthesized T1-Ag-NPs and T2-AgN-Ps showed DNA nuclease activity at all tested concentrations. Moreover, both new synthesized Ag-NPs had antimicrobial activity against the strains studied, especially on Gram positive bacteria. T1-Ag-NPs and T2-AgNPs also showed powerful Escherichia coli growth inhibition. The highest biofilm inhibition percentages of T1-Ag-NPs and T2-Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus were 100.0%, respectively, at 500 mg/L.

Novel reusable and switchable deep eutectic solvent for extraction and determination of curcumin in water and food samples.

For the first time, a fast and easy extraction method based on a unique reusable and switchable deep eutectic solvent (made of octylamine, succinic acid, and water as precursors) was presented and utilized for the microextraction and determination of curcumin as a model analyte. The main factors used to induce a phase transition in the as-prepared deep eutectic solvent were solutions of NaOH and HCl. Among the standout characteristics of the suggested deep eutectic solvent are the removal of toxic organic solvents like THF, the lack of a need for centrifugation, and the ability to be reused in subsequent extractions. The influence of effective parameters (i.e., proportions of deep eutectic solvent structure components, volume of prepared deep eutectic solvent, volume and concertation of NaOH, volume of HCl, and salt effect) on the extraction procedure were investigated. The calibration curve also was linear in the range of 35-500 µg L-1 with coefficients of determination (R2) of 0.9976. Limit of detection (S/N = 3) 10.0 µg L-1, the limit of quantification (LOQ) of 35.0 µg L-1, the relative standard deviations (RSDs %) composed of intra-day RSD (4.7) and inter-day RSD (6.4), preconcentration factor of 40.0, enrichment factor of 38.68, and relative recovery of 92.6%-100.3 % were achieved. The reusable and switchable deep eutectic solvent based-dispersive liquid-liquid microextraction technique was proficiently employed to expedite easy and fast extraction of curcumin from water and food samples.

Nanodiamond (ND)-Based ND@CuAl2O4@Fe3O4 electrochemical sensor for Tofacitinib detection: A unified approach to integrate experimental data with DFT and molecular docking.

Tofacitinib (TOF) is gaining recognition as a potent therapeutic agent for a variety of autoimmune disorders, including rheumatoid arthritis and psoriasis. Ensuring precise drug concentration control during treatment necessitates a rapid and sensitive detection method. This study introduces a novel electrochemical sensor employing a composite of nanodiamond (ND), copper aluminate spinel oxide (CuAl2O4), and iron (II, III) oxide (Fe3O4) as modified materials for efficient TOF detection. Extensive analyses using physicochemical and electrochemical techniques were carried out to characterize the morphological, structural, and electrochemical properties of the ND@CuAl2O4@Fe3O4 composite. Thereafter, various voltammetric methods were utilized to evaluate the electrochemical behavior of the ND@CuAl2O4@Fe3O4-modified glassy carbon electrode (GCE) concerning TOF determination. The fabricated electrode showcased superior performance in electrochemical TOF detection in a buffered solution (pH = 5), achieving a remarkably low detection limit of 7.8 nM and a linear response from 0.05 µM to 13.21 µM. Furthermore, applying the modified electrode as an electrochemical sensor exhibited exceptional selectivity, stability, and practicality in determining TOF in pharmaceutical and biological samples. Alongside the sensor development, this study conducted a thorough investigation using Density Functional Theory (DFT) for the geometry optimization of TOF and the TOF-ND complex. Consequently performed molecular docking studies using Janus Kinase 1 (JAK1) (PDB ID: 3EYG) and JAK3 (PDB ID: 3LXK) indicated higher interaction of the TOF-ND conjugate with the JAKs, reflected by binding energies of -12.9 kcal/mol and -11.7 kcal/mol for JAK1 and JAK3 respectively, compared to -7.0 kcal/mol and -6.9 kcal/mol for TOF alone. These findings illustrate the potential of the ND-based ND@CuAl2O4@Fe3O4 composite as a proficient sensing material for TOF detection and the merits of DFT in providing a detailed understanding of the interactions at play. This pioneering research holds promise for real-time TOF monitoring, which will advance personalized treatment strategies and improve therapeutic outcomes for patients with autoimmune disorders.

Fe3O4-SiO2-MIL-53 (Fe) nanocomposite for magnetic dispersive micro-solid phase extraction of cadmium (II) at trace levels prior to HR-CS-FAAS detection.

A magnetic metal-organic framework Fe3O4-SiO2-MIL-53 (Fe) nanocomposite was synthesized for magnetic dispersion micro-solid phase extraction (M-d-µSPE) of cadmium in water, spice, chocolate, tea, and tobacco samples prior to the detection by flame atomic absorption spectrometry. Fe3O4-SiO2-MIL-53 (Fe) nanocomposite fabricated using the solvothermal technique was characterized using a field emission scanning electron microscope and X-ray diffraction. The extraction efficiency of the method was improved by optimizing the experimental factors. After optimization, the linearity range for Cd (II) was 4.3-500 µgL-1. The limits of detection and quantification were 1.3 and 4.3 µgL-1, respectively. The presented magnetic dispersion-micro solid phase extraction method was applied to Cd (II) analysis in food and some environmental samples.

Metal-organic framework functionalized with deep eutectic solvent for solid-phase extraction of Rhodamine 6G in water and cosmetic products.

An NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized for extraction and determination of Rhodamine (Rh) 6G from environmental and cosmetic samples. The deep eutectic solvent (DES) was prepared by mixing choline chloride and urea in a mole ratio of 1:2. NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized using the impregnation method at a ratio of 60:40 (w/w). The optimum conditions were determined after NH2 -MIL-53(Al)-DES(ChCl-Urea) characterization was performed. The optimum conditions were determined as pH 8, adsorbent amount of 15 mg, total adsorption-desorption time of 6 min, and enrichment factor of 20. The recovery values of the solid-phase extraction method for water and cosmetic samples under optimum conditions were between 95% and 106%. NH2 -MIL-53(Al)-DES(ChCl-Urea) nanocomposite was an economically advantageous adsorbent because of its reusability of 15 times. All analyses were performed using the ultraviolet-visible spectrophotometer. The linear range, limit of detection, and limit of quantification of the method were 100-1000, 9.80, and 32.68 µg/L, respectively. The obtained results showed that the synthesized nanocomposite is a suitable adsorbent for the determination of Rh 6G in water and cosmetic samples. The real sample applications were verified with the high-performance liquid chromatography system.

A magnetic solid phase extraction procedure for Pb(II) at trace levels on magnetic Luffa@TiO2 in food and water samples.

A novel magnetic Luffa@TiO2 sorbent was synthesized and characterized by using XRD, FTIR and SEM techniques. Magnetic Luffa@TiO2 was used for solid phase extraction of Pb(II) in food and water samples prior to its flame atomic absorption spectrometric (FAAS) detection. The analytical parameters such as pH, adsorbent quantity, type and volume of eluent, and foreign ions were optimized. Analytical features such as the limit of detection (LOD) and the limit of quantification (LOQ) of Pb(II) are 0.04 µg L-1 and 0.13 µg L-1 for liquid samples and 0.159 ng/g and 0.529 ng/g for solid samples, respectively. The preconcentration factor (PF) and relative standard deviation (RSD%) were found 50, and 4 % respectively. The method was validated by using three certified reference materials (NIST SRM 1577b bovine liver, TMDA-53.3 and TMDA-64.3fortified water). The presented method was applied to lead contents of some food and natural water samples.

An electrochemical sensing platform with a molecularly imprinted polymer based on chitosan-stabilized metal@metal-organic frameworks for topotecan detection.

The present study aims to develop an electroanalytical method to determine one of the most significant antineoplastic agents, topotecan (TPT), using a novel and selective molecular imprinted polymer (MIP) method for the first time. The MIP was synthesized using the electropolymerization method using TPT as a template molecule and pyrrole (Pyr) as the functional monomer on a metal-organic framework decorated with chitosan-stabilized gold nanoparticles (Au-CH@MOF-5). The materials' morphological and physical characteristics were characterized using various physical techniques. The analytical characteristics of the obtained sensors were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). After all characterizations and optimizing the experimental conditions, MIP-Au-CH@MOF-5 and NIP-Au-CH@MOF-5 were evaluated on the glassy carbon electrode (GCE). MIP-Au-CH@MOF-5/GCE indicated a wide linear response of 0.4-70.0 nM and a low detection limit (LOD) of 0.298 nM. The developed sensor also showed excellent recovery in human plasma and nasal samples with recoveries of 94.41-106.16 % and 95.1-107.0 %, respectively, confirming its potential for future on-site monitoring of TPT in real samples. This methodology offers a different approach to electroanalytical procedures using MIP methods. Moreover, the high sensitivity and selectivity of the developed sensor were illustrated by the ability to recognize TPT over potentially interfering agents. Hence, it can be speculated that the fabricated MIP-Au-CH@MOF-5/GCE may be utilized in a multitude of areas, including public health and food quality.

A fungal functionalized magnetized solid phase extractor for preconcentrations of Pb(II), Mn(II), and Co(II) from real samples.

Due to increasing industrialization and overpopulation, the amount of toxic metals is increasing in the environment, including air, soil, water, and food. Solid phase extraction is an efficient and ideal technique to preconcentrate the toxic metals before their measurements by analytical instruments. Russula brevipes was immobilized on γ-Fe2O3 magnetic nanoparticles and employed as a SPE sorbent to preconcentrate the trace level of Pb(II), Mn(II), and Co(II). To investigate the extraction conditions, significant experimental parameters were examined in details. LODs were calculated as 0.022, 0.015, and 0.024 ng mL-1 for Pb(II), Mn(II), and Co(II), respectively. The biosorption capacities of R. brevipes immobilized γ-Fe2O3 were calculated as 43.1 mg g-1 for Pb(II), 54.9 mg g-1 for Mn(II), and 49.7 mg g-1 for Co(II). Pb(II), Mn(II), and Co(II) in food samples at trace levels were preconcentrated by applying the developed method.

Application of magnetic solid-phase extraction for sensitive determination of anticancer drugs in urine by means of diamino benzidine tetrachlorohydrate modified magnetic nanoparticles.

BACKGROUND: The analysis of drug active molecules and residues in the treatment of cancer is important for the sustainability of human life and therapeutic effects. For this purpose, a new magnetic sorbent was developed to use in solid phase extraction prior to conventional high-performance liquid chromatography (HPLC) analysis of Paclitaxel (PAC) and Gemcitabine (GEM) molecules. METHODS: In this study, a separation and pre-concentration approach based on magnetic solid phase extraction (MSPE) was proposed for PAC and GEM by means of using a newly synthesized magnetic sorbent. After the MSPE procedure, an HPLC system with a diode array detector (DAD) was used to analyze trace amounts of PAC and GEM anticarcinogenic drugs in urine samples. Surface modification of magnetic Fe3O4 nanoparticles was carried out by diaminobenzidinetetrachloro hydrate (DABTC) for the first time and a useful sorbent was obtained for MSPE experiments. RESULTS: In the proposed method, PAC and GEM molecules were retained on the c in the presence of a pH 5.0 medium and desorbed to 300 µL of acetonitrile: methyl alcohol (1:1) eluent phase before HPLC-DAD analysis. Under the optimized conditions, the limit of detection (LOD) values for PAC and GEM were 1.38 and 1.44 ng mL-1 while the enhancement factor for PAC and GEM were 139.5 and 145.3, respectively. The relative standard deviations (RSD %) for PAC and GEM were below 3.50% in inter-day repeated experiments by means of model solutions containing 100 ng mL-1 drug active ingredients. CONCLUSIONS: Synthesis and characterization of DABTC-Fe3O4 nanoparticles were performed using suitable methodologies. Optimization of MSPE was done step by step. And finally, the developed method was successfully applied to urine samples with quantitative recoveries in the range of 99.0% and 105.0%.

Molecularly imprinted polymer film loaded on the metal-organic framework with improved performance using stabilized gold-doped graphite carbon nitride nanosheets for the single-step detection of Fenamiphos.

A noninvasive material-based electrochemical sensor continuously monitors the fenamiphos (FMS) level in vegetable samples is highly desirable for innovative fabrics to check the health of agricultural products. Herein, an electrochemical sensor is fabricated by a sensitive molecularly imprinted polymers/metal-organic framework/gold stabilized on graphite carbon nitride (MIP-Au@MOF-235@g-C3N4) for monitoring the FMS level in real samples continuously with high sensitivity and accuracy. The MIP-based sensor was simply produced by a hydrothermal strategy. The MIP-Au@MOF-235@g-C3N4 had a large specific surface area and high catalytic activity, which enables the fabricated sensor with good electrochemical performance with a high sensitivity of 1.07 µA.µM-1 and a wide linear range of 0.01 to 16.4 µM. The proposed strategy was applied to determine FMS in agricultural products with satisfactory recoveries (94.7-107.9%) and a relative standard error of less than 1.0%, providing novel tactics for the rational design ofMIP-sensorsto determine a growing number of deleterious substances.

Innovative molecularly imprinted electrochemical sensor for the nanomolar detection of Tenofovir as an anti-HIV drug.

Tenofovir (TNF) is an antiviral medicine that is utilized to treat the human immunodeficiency virus (HIV). However, its level must be controlled in the human body and environment at the risk of causing kidney and liver problems. Therefore, determining TNF concentration in real samples with more advanced, inexpensive, and accurate sensing systems is essential. In this work, a novel electrochemical nanosensor for TNF determination based on molecularly imprinted polymer (MIP) on the screen-printed electrode modified with functionalized multi-walled carbon nanotubes, graphite carbon nitride, and platinum nanoparticles (MIP-Pt@g-C3N4/F-MWCNT/SPE) was constructed through the electro-polymerization approach. The molecularly imprinted polymers were prepared on the electrode surface with TNF as the template molecule and 2-aminophenol (2-AP) as the functional monomer. Moreover, factors that affect sensor response were optimized. Pt@g-C3N4/F-MWCNT nanocomposite had an excellent synergistic effect on MIP, allowing rapid and specific identification of the test substance. The results demonstrated that the electro-polymerization of 2-AP supplies large amounts of functional groups for the binding of the template molecules, which remarkably enhances the sensitivity and specific surface area of the MIP sensor. This surface enlargement increased the analyte accessibility to imprinted molecular cavities. Under optimum conditions, the oxidation peak current had a linear relationship with TNF concentration ranging from 0.005 to 0.69 µM with a low detection limit of 0.0030 µM (S/N = 3). The results demonstrated that the designed MIP sensor possesses acceptable sensitivity, repeatability, and reproducibility toward TNF determination. Moreover, the developed sensor was applied to biological and water samples to determine TNF, and satisfactory recovery results of 95.6-104.8% were obtained (RSD less than 10.0%). We confirm that combining as-synthesized nanocomposite Pt@g-C3N4/F-MWCNT with MIP improves the limitations of MIP-based nanosensors. The proposed electrode is also compatible with portable potentiostats, allowing on-site measurements and showing tremendous promise as a point-of-care (POC) diagnostic platform.

Arsenic speciation by using emerging sample preparation techniques: a review.

Arsenic is a hazardous element that causes environmental pollution. Due to its toxicological effects, it is crucial to quantify and minimize the hazardous impact on the ecology. Despite the significant advances in analytical techniques, sample preparation is still crucial for determining target analytes in complex matrices. Several factors affect the direct analysis, such as trace-level analysis, advanced regulatory requirements, complexity of sample matrices, and incompatible with analytical instrumentation. Along with the development in the sample preparation process, microextraction methods play an essential role in the sample preparation process. Microextraction techniques (METs) are the newest green approach that replaces traditional sample preparation and preconcentration methods. METs have minimized the limitation of conventional sample preparation methods while keeping all their benefits. METs improve extraction efficacy, are fast, automated, use less amount of solvents, and are suitable for the environment. Microextraction techniques with less solvent consumption, such as solid phase microextraction (SPME) solvent-free methods, and liquid phase microextraction (LPME), are widely used in modern analytical procedures. SPME development focuses on synthesizing new sorbents and applying online sample preparation, whereas LPME research investigates the utilization of new solvents.

Design, Structural Characteristic and Antibacterial Performance of Silver-Containing Cotton Fiber Nanocomposite.

In the present study, cotton fiber was treated with phosphorus trichloride in the presence of oxygen. As a result of the subsequent hydrolysis of modified cotton fibers, phosphorus-containing fragments with acidic groups and chlorine atoms were introduced onto their surface. Afterward, silver-containing composites based on raw and modified cotton fibers were prepared using the chemical reduction method. The obtained samples were characterized in detail by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray powder diffraction, as well as by thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. A comparative bioassay experiment of four samples for gram-negative (Escherichia coli) bacteria, gram-positive (Staphylococcus aureus) bacteria, and the fungus Candida albicans was carried out. These results showed the predominant antibacterial activity of the phosphorylated sample and the composite based on it. Thus, the development of these antibacterial cotton fibers using readily available reagents under relatively mild conditions could be used as potential industrial applications for the production of everyday medical textiles.