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Millions of people worldwide are adversely affected by Arsenic continuing exposure, so providing arsenic-free consumption of water is an immense task for the researchers. The chemistry, content of arsenic-contaminated water as well as adsorption play a big role in arsenic elimination. The mechanism of adsorption technology's elimination of As (V) from the water was simply presented as the elements that govern various adsorption paths. The effects of a variety of adsorbents on As (V) elimination from aquatic were explored in the present research, which classified the materials used as adsorbents based on physical, chemical, and biological processes. When choosing an adsorbent, adsorption capability is an important factor to consider. As a result, developing As (V) elimination from aquatic adsorption strategies includes developing environmentally acceptable materials with effectual adsorption abilities, refining the preparation and alteration procedures of recent adsorbents, and boosting renewal effectiveness. After choosing a particular adsorbent for As (V) elimination from water, regional features of arsenic-polluted water, applied viability of the adsorption process, besides suitable environments of respectively material must be extensively reviewed and analyzed. The current study gives an outline of the adsorption technique to remove arsenic from wastewater, as well as the adsorption capacity of various adsorbents.

Powdered Teucrium polium leaves (S1) were modified with zinc chloride (ZnCl2) (S2), a mixture of copper sulfide (CuS) and ZnCl2 (S3), and oxalic acid (H2C2O4) (S4). The porosity, surface area, and functional groups of these four samples, along with their ability to uptake KMnO4 from solutions, were inspected to identify the optimal adsorbent. For KMnO4 adsorption by the ideal adsorbent (S2), the pHZPC (pH value at which the adsorbent surface is uncharged), influences of experimental circumstances, and dynamic, isotherm, and thermodynamic parameters were examined. According to the results, the surface area, pore size, pore volume, and pHZPC of the optimum adsorbent (S2) are 3.689 m2/g, 570.20 Å, 0.01776 cm3/g, and 6.4, respectively. The optimal S2 dose, the ideal value of pH solution, and equilibrium time are 0.05 g, 5.5, and 192 min, respectively. The Langmuir and second-order models are appropriate for modeling this adsorption. Furthermore, increasing the temperature from 27 to 57°C increases the maximum adsorption capacity (q max) from 833.33 to 1000.00 mg/g. According to the thermodynamic data, this adsorption is both endothermic and spontaneous.

We report a method where the refractive index increments of an iron storage protein, ferritin, and apoferritin (ferritin minus iron) were measured over the wavelength range of 450–678 nm to determine the average iron content of the protein. The protein used in this study had ∼3375 iron atoms per molecule. The measurement of optical dispersion over the broad wavelength range was enabled by the use of mesoporous leaky waveguides (LWs) made of chitosan. We present a facile approach for fabricating mesoporous chitosan waveguides for improving the measurement sensitivity of macromolecules such as ferritin. Mesoporous materials allow macromolecules to diffuse into the waveguide, maximizing their interaction with the optical mode and thus increasing sensitivity by a factor of ∼9 in comparison to nonporous waveguides. The sensitivity was further improved and selectivity toward ferritin was achieved by the incorporation of antibodies in the waveguide. The method presented in this work is a significant advance over the state of the art method, the enzyme linked immunosorbent assay (ELISA) used in clinics, because it allows determining the average content of ferritin in a single step. The average iron content of ferritin is an important marker for conditions such as injury, inflammation, and infection. Thus, the approach presented here of measuring optical dispersion to determine the average iron content of ferritin has a significant potential to improve the point of care analysis of the protein for disease diagnosis and screening.

Phthalocyanines are of a broad interest in photovoltaic applications. In this study, films of titanium-phthalocyanine-chloride (TiPcCl2) were prepared by the thermal evaporation method. The molecular structure was studied by Raman spectrometer, showing a match between the spectra of the powder and the prepared films. The films' surface was examined by the atomic force microscope, revealing grain size and surface roughness of TiPcCl2 thin films to be 223 and 41 nm, respectively, for a 100 nm thickness. The energy gap was determined to be 1.5 eV, with no observable effect by the thickness change. Additionally, the linear and nonlinear optical constants were calculated from reflectance and transmittance measurements. The values of third nonlinear susceptibility are in order of 10− 12 esu, which is compatible with other phthalocyanines. The nonlinear optical constants indicate that TiPcCl2 films could also be used for optical laser limiters.

A novel adsorbent prepared from the leaf powder of Teucrium polium L. (TPLLP) was characterized and its ability for adsorption of Cong red (CR) was inspected. Influences of CR concentration, adsorbent dosage, time of agitation, pH of solution, and temperature on the performance of this adsorption were also examined. Three models of kinetic along with three different isotherm models were applied for analyzing the empirical data of this adsorption. Additionally, the thermodynamic constants of were decided. The surface area, pore volume, pore size, and pHZPC of Zn/Cu-TPLLP were found to be 2.6436 m2.g-1, 0.013317 cm3.g-1, 527.393 Å, and 8.8, respectively. The achieved outcomes indicate the positive influence of temperature, concentration of CR in the range of 20 to 900 mg/L, adsorbent mass in the range of 0.005 to 0.02 g, time of adsorption from 0 to 120 min, and pH from 5.5 to 8.5. Models of the 2nd order with R 2 ≥ 0.995 and Langmuir with R 2 ≥ 0.990 were the best among the other kinetic and isotherm models applied in this research. Moreover, superior capacities of 526.32, 666.67, and 909.09 (mg.g-1) were stemmed at 27, 42, and 57°C, respectively. The outcomes of the thermodynamic evidenced that this adsorption is spontaneous and a heat absorber.

This proof-of-principle study demonstrates the feasibility of a leaky waveguide (LW) aptasensor, where aptamers were immobilised in a mesoporous chitosan waveguiding film for the detection of thrombin. This work has demonstrated that aptamers immobilised in hydrogels retain their affinity and selectivity towards their target and thus can be used as bioreceptors. The use of antibodies as bioreceptors for sensing thrombin is not viable because it is a serine protease, which will cleave the antibodies. Currently used assays based on clotting time and chromogenic/fluorogenic substrates have limited potential for thrombin measurement in whole blood. Using the initial binding rate over the first 5 min, the limit of detection of our LW aptasensor for thrombin was ∼22 nM. The sensor was tested with spiked serum samples, giving a reading of 46.1 ± 4.6 nM for a sample containing 50 nM thrombin. Our proposed sensor combines the robustness and low cost of aptamers as molecular recognition elements with the simple fabrication process of the chitosan-based leaky waveguide, making LW aptasensors highly attractive for applications in point-of-care diagnostics and healthcare monitoring.

Average iron content of ferritin has a potential to serve as a biomarker for early identification of high-risk trauma patients at point-of-care (PoC). Appropriate therapies can then be administered to reduce morbidity and mortality. Currently, protein and iron levels are measured separately using enzyme-linked immunosorbent assay (ELISA) and UV or atomic absorption spectroscopy (AAS) respectively, but the use of two completely different methods adds to the complexity and analysis time of the combined measurement. As a result, these methods are unsuitable for PoC analysis. To address this gap, we report a biosensor for measuring the average iron content of ferritin in a single step. The biosensor was based on a dye-doped leaky waveguide (LW), which operates in the entire visible wavelength range, and hence allowed the measurement of differences in the optical dispersion of ferritin and apoferritin to determine the average iron content of the protein. The LW biosensor comprised a 1.54 micron thick mesoporous chitosan slab waveguide with immobilized antibodies against ferritin/ apoferritin to measure the optical dispersion of 110 nM protein. Based on the baseline noise, the limit of detection for this method is ~700 pM for ferritin/ apoferritin. The biosensor has a significant potential for PoC measurement of the average iron content of serum ferritin and, in future, the total protein cencentration.