Polymethacrylate Matrix Research Articles

Stabilization of gold nanoparticles in a transparent polymer while maintaining the capabilities of a colorimetric glucose sensor

We suggest optical sensor systems based on the gold nanoparticles embedded within the polymethacrylate matrix for dual-signal spectrophotometric and colorimetric approaches can be used for the determination of glucose in the range of 0.1–0.8 mM and 0.3–0.8 mM with the detection limits of 0.06 mM and 0.1 mM, correspondingly. We studied the conditions of interaction between the gold nanoparticles, iodide and glucose by evaluating the influence of such factors as the contact time, pH and the analyte concentration upon the analytical signal.

Stabilization of silver nanoparticles in a transparent polymethacrylate matrix while maintaining the capabilities of a colorimetric hydrogen peroxide sensor

Stabilization of silver nanoparticles in a transparent polymethacrylate matrix while maintaining the capabilities of a colorimetric hydrogen peroxide sensor

Comparison of methods for the synthesis of silver nanoparticles stabilized in a solid polymethacrylate matrix

Silver nanoparticles were synthesized inside the small plates of transparent polymer medium by reduction of silver cations. The difference in morphology and sizes of nanoparticles synthesized by chemical, photochemical and thermal reduction was revealed, which depends both on the component ratio of the mixture and on the reduction time for the specific component ratio The polymethacrylate matrix itself acts as the stabilizing agent. A colorimetric sensor based on polymethacrylate matrix and silver nanoparticles was developed for the detection of hydrogen peroxide. The optical properties of the sensor were characterized by spectrophotometer using the surface plasmon resonance. A colorimetric sensor with nanoparticles undergoing to thermal reduction showed a quick result for the determination of hydrogen peroxide in the range 0.2–4.4 mM with a detection limit 0.1 mM.

Solid-phase Spectrophotometric Determination of Synthetic Food Colourants in Confectionery Products

Abstract: We suggest a simple method of solid-phase spectrophotometric determination of the following synthetic food colourants: quinoline yellow Е104, sunset yellow FCF Е110, Ponceau 4R Е124, patent blue V Е131, brilliant blue FCF Е133. Methods: The method implies the use of a polymethacrylate matrix for solid-phase extraction of these colourants from confectionery products. Results: While the contact time for the matrix and the colourant solution was 15 minutes, the detection limits were 1.7; 1.6; 5.8; 2.9; 2.9 mg·L–1 for colourants E104, E110, E124, E131, E133, correspondingly. The standard deviation of the results by determination of synthetic food colourants in confectionery products did not exceed 13 %. Conclusion: Compared to spectrophotometric determination involving liquid solvent extraction, the method of determination of synthetic colourants we developed offers the following advantages: sufficient increase of determination sensitivity, which results from accumulation of the analyte and elimination of the possible aliquote turbidity as well as zero colourant loss by absorption into supernatant liquid and the solid phase of the matrix.

Dispersion of Cellulose Nanofibers in Methacrylate-Based Nanocomposites.

Poly(methylmethacrylate-co-methacrylic acid) (PMMA-co-MAA) polymers were prepared via cobalt-mediated free radical copolymerization and were characterized after synthesis. The synthesis led to a 98.5% conversion and a final ratio between the two units, MMA/MAA, was equal to 63:37 mol%. PMMA-co-MAA was then used as a matrix for cellulose-based nanocomposites to tailor filler compatibility, thanks to the presence of carboxylic groups capable of generating strong H-bonds with the cellulose surface. Cellulose nanofibers (CNFs) were dispersed using a solution with a mixture of two solvents to tailor compatibility of both the components. For this purpose, CNFs were successfully re-dispersed in methanol using the solvent exchange method and tetrahydrofuran/methanol mixtures at different ratios were used for the preparation of the films. Fully transparent films of PMMA-co-MAA + CNF were prepared up to 15 wt% of CNF with a good dispersion in the matrix. This dispersion state leads to the reinforcement of the polymethacrylate matrix, increasing its tensile strength whilst preserving optical transparency.

Digital image colorimetry method for determination of glucose using silver nanoparticles immobilized into polymethacrylate matrix

We suggest Ag0 nanoparticles immobilized into transparent polymethacrylate matrix (PMM–Ag0) as a simple colorimetric sensor for determination of glucose. We demonstrate the capabilities of a smartphone to process the images and further analyze the information obtained by determination of glucose using PMM–Ag0 sensor. The method can be employed for glucose concentrations of 0.1–4.3 mmol dm−3, while its detection limit is 0.05 mmol dm−3.

Application of interval estimations of the total content of antioxidants for the analysis of juice products by the CUPRAC method using the Cu(II) – NC–PMM system

Сu(II) – neocuproinе indicator system (CUPRAC method, R. Apak) was used for spectrophotometric determination of the total content of antioxidant reductants (ΣAO) in juice products. Gallic acid, ascorbic acid, quercetin, luteolin, dihydroquercetin, which are typical for fruit and berry juices, as well as trolox, as a frequently used standard, were used as model compounds of antioxidant-reducing agents (AO). The polymethacrylate matrix (PMM) with immobilized reagents was immersed in the test solution for 20 minutes, and then photometrically measured at 450 nm. The aim of the work was to compare two methods for estimating ΣAO: a) in terms of the content of a standard substance (generally accepted method); b) in the form of an interval calculated taking into account the sensitivity coefficients when determining different AO at a selected wavelength (interval estimate according to V.I. Vershinin). It was established that the analytical signals of the model AO obeyed the Beer-Lambert-Bouguer law in the range of 10–6–2.10–5 mol/l, and were measured with a relative standard deviation not exceeding 10 %; deviations from the light absorption additivity of AO mixtures were statistically insignificant. As in the photometry of solutions, the sensitivity coefficients of different AO were different, and the differences decreased when using «normal» concentrations. The modulus of the relative error in estimating ΣAO in model mixtures, even when using optimal standards (luteolin), reached 17%. The possibility of interval estimation of ΣAO from generalized analytical signals measured by the CUPRAC method using PMM matrices was shown. The boundaries of the intervals practically did not depend on the standards used during the calculation. For all mixtures the actual values of ΣAO were within the boundaries of the corresponding intervals. The results of the group analysis of fruit and berry juices before and after their dilution confirmed the approximate correctness of the results obtained both by method (a), i.e. in terms of luteolin, and by method (b), i.e. in the interval form. Unfortunately, the width of the intervals that take into account the intragroup signal intensity was an order of magnitude larger than the width of the confidence intervals calculated from the results of repeated measurements of generalized signals (Student's test, n = 3, P = 0.95). This indicates the necessity of leveling the sensitivity coefficients for different AO. Thus, both methods of calculation are suitable for the group analysis of juice products, but method (b) leads to more reliable, more metrological correct, but less unambiguous estimates of the total content of the antioxidants.

Rapid colorimetric determination of ascorbic acid by solid phase extraction of iodine into a polymethacrylate matrix

The proposed iodometric solid-phase spectrophotometry method is based on interaction of ascorbic acid with molecular iodine in a solution with further extraction of the unreacted iodine into a polymethacrylate matrix followed by its spectrophotometric measurement in the solid phase. The amount of iodine extracted by the matrix is in inverse linear dependence on the concentration of ascorbic acid in the solution. The method can be employed for the range of ascorbic acid concentrations 1.0–9.0 mg dm–3, while its detection limit is 0.8 mg dm–3.

Smartphone-based colorimetric determination of fluoride anions using polymethacrylate optode

We developed a new transparent polymer optode based on polymethacrylate with Zr(IV) and alizarin red complex immobilized into it for digital colorimetric and solid-phase spectrophotometric determination of fluoride anions. The matrix changes its colour from purple to yellow after it contacts fluoride anion. We developed a processing algorithm for coloured images which helps calculate mean value for the RGB colour-coordinate system in a selected optode image and translates it into a fluoride concentration value. The analytical signal of the suggested method has a linearity range of 0.1–30 mg⋅L−1 with the detection limit 0.03 mg⋅L−1. Compared to other methods, the modified polymethacrylate matrix is actually a ready-to-use colorimetric system offering rapid results for drinking water quality control.

Colorimetric determination of bromate in drinking water using methyl red immobilized into polymethacrylate matrix

ABSTRACT This article presents solid-phase spectrophotometric method of bromate determination using methyl red immobilised into transparent polymethacrylate matrix. The method is based on oxygenation of the indicator immobilised into the matrix by a bromate. We discovered the optimal conditions for bromate determination, studied the effect of interference of the foreign ions, and evaluated the analytical performance of the suggested method. The method we developed makes it possible to quantify the content of a bromate in the concentration range of 0.1–1.0 mg·L−1 with the limit of detection 0.01 mg·L−1. The mean relative standard deviation of the results was ≤1.2%, which confirmed reproducibility of this assay technique. We demonstrated usability of the suggested method for detection of bromates in drinking water using solid-phase spectrophotometry without any preliminary sample preparation. Polymethacrylate matrix with methyl red immobilised into it can be used as a ready-made analytical form for the rapid visual bromate determination test.

On the Use of Surfactant‐Complexed Chitosan for Toughening 3D Printed Polymethacrylate Composites

AbstractThis work reports a simple approach to prepare toughened 3D‐printed polymethacrylate (PMA) composites using surfactant‐modified chitosan (SMCS) particles at loadings between 2–10 wt%. Chitosan (CS) is modified with anionic surfactant, sodium dodecyl sulfate, via ionic complexation to facilitate compatibility and dispersion of CS to PMA matrix by non‐covalent interactions between the components. The study successfully demonstrates high‐accuracy 3D printing of composites with significant improvements in the overall mechanical properties. The composite with the best loading of 8 wt% SMCS shows a tensile modulus of 1.23 ± 0.05 GPa, a tensile strength at 49.8 ± 0.96 MPa, a yield stress at 33.3 ± 1.48 MPa, and a strain‐at‐failure 10.3 ± 0.61%, which are 45%, 40%, 32%, and 68% higher than neat PMA, respectively. This provides a significant improvement in toughness at 4.92 ± 0.55 MJ m−3 for the composite, 184% higher than that of neat PMA. The marked increase in toughness is due to enhanced filler‐matrix interactions which improve the ability of the 3D printed composite to absorb energy under tensile load. The results from this work provide new understandings into the strategies for design and preparation of stereolithography 3D printed materials reinforced with toughening fillers from renewable resources.

Determination of antioxidant capacity of medicinal tinctures using cuprac method involving Cu(II) neocuproine immobilized into polymethacrylate matrix

This work suggests using Cu(II) - neocuproine redox system immobilized into transparent polymethacrylate matrix for assessment of antioxidant capacity using CUPRAC method. The method we developed makes it possible to quantify the content of the antioxidants in the concentration range of 5.9×10-8-9.1×10-5M. The sensor was tolerant to pH variations and painting, and used for the antioxidant capacity determination values of some commercial medicinal tinctures without pretreatment.

Colorimetric and fluorescent sensing of rhodamine using polymethacrylate matrix.

This is a description of the tracer analysis method involving colorimetric and fluorescent measurements based on solid phase extraction of rhodamine into transparent polymethacrylate matrix. Concentration of rhodamine in PMM is measured as spectrophotometric absorption level at 535 nm and fluorescence at 554 nm. The calibration graphs are linear within the ranges 0.02-0.10 mg∙L-1 and 0.002-0.06 mg∙L-1 and detection limits 0.014 mg∙L-1 and 0.0005 mg∙L-1 are calculated for colorimetric and fluorescent measurements, respectively. The method has been successfully used for determination of rhodamine in groundwater.

Colorimetric determination of food colourants using solid phase extraction into polymethacrylate matrix

This paper describes a simple colorimetric method for determination of Brilliant Blue, Sunset Yellow, Ponceau 4R and Tartrazine using transparent polymer optode. The method provided acceptable linear ranges 0.01–3.0 mg L−1 with correlation coefficients higher than 0.995 under the optimal conditions. Commercial beverages and juices containing different amounts of food dyes were analyzed and the results were compared to those obtained by HPLC.

Choline based polymethacrylate matrix with pharmaceutical cations as co-delivery system for antibacterial and anti-inflammatory combined therapy

Anionic drugs, i.e. salicylate (Sal−) and sulfacetamide (Sfc−) were chosen as counterions in trimethylammonium based poly(meth)acrylates. These ionic systems with amphiphilic properties were used to form polymeric systems for dual drug delivery by loading of nonionic pharmaceutics like immunosuppressant quercetin (QUE), anti-inflammatory indomethacin (IMC) and antibiotic erythromycin (ERY). The latter one was loaded with high efficiency (>60%), whereas poorer loading efficiency was obtained for aromatic compounds (<10%) because of strong repulsing effect with ionic moieties in polymer matrix. Coordinating and polar properties of anions as the additional factors in drug-polymer affinity can be applied to adjust the drug loading and release. The polymer particles resulted in aqueous solutions were characterized by hydrodynamic diameters (70–430 nm) and zeta potentials (20–65 mV) indicating specific multifactor action/contraction of drug delivery system (DDS) components. The release profiles of both type drugs demonstrated typical diffusion process with burst effect during initial 2 h, and then it slowed down for next 80 h. The release rate of bioactive anions in the dual system was not affected by the presence of nonionic drug showing comparable kinetics profile with the analogical single drug system carrying ionic drug. The most promising Sal-based and ERY-loaded polymer system was able to release ~60% of ionic drug (via exchange with phosphate anions in buffer solution) and ~70% of nonionic drug. The biological studies on the proposed polymeric systems were conducted indicating no toxic activity against human cells (NHDF and BEAS-2B), no gene expression for anti-inflammatory interleukins IL6 and IL8 as well as the antibacterial activity was observed against E. coli.

Solid phase colorimetric determination of iodine in food grade salt using polymethacrylate matrix

A novel colorimetric sensor has been proposed for sensitive and accurate detection of iodine forms using polymethacrylate matrix, which also has the outlook for use with samples without pre-treatment and is suitable to fit in a portable instrument for in situ iodine analysis. This determination method is based on interaction of polymethacrylate matrix with iodine forms followed by measurement of absorbance at 370 nm. The principle of this colorimetric sensor is not ordinary colorimetry, but a new colorimetric strategy that combines solid phase extraction and spectrophotometric determination of a target substance following completion of the color change processes. This method ensures determination of 0.05–80.0 µg·g−1 of iodine with the detection limit of 0.02 µg·g−1. The testing results show that this polymethacrylate matrix can be used for determination of iodine in solutions, food grade salt and iodinated mineral water.

Transparent polymer sensor for visual and photometrical detection of thiocyanate in oilfield water

A novel colorimetric sensor has been proposed for sensitive and accurate visual and spectrophotometric detection of thiocyanate using polymethacrylate matrix, which also has the potential for use with samples without pretreatment. The determination method is based on shaping of a Fe3+-thiocyanate colored complex into a transparent polymer matrix, followed by measurement of absorbance at 490 nm. The principle of this colorimetric sensor is not ordinary colorimetry, but a new colorimetric strategy that combines solid phase extraction and spectrophotometric determination of thiocyanate following completion of the color change processes. The method ensures determination of 0.8–30.0 mg L−1 of thiocyanate with the detection limit of 0.3 mg L−1. The proposed simple method makes it possible to determine visually in the concentration above 6.0 mg L−1 using a color scale. The test results show that the polymethacrylate matrix can be used for determination of thiocyanate in oilfield water.

Kinetic Determination of Thiocyanate by the Reaction of Bromate with Crystal Violet Immobilized in a Polymethacrylate Matrix

A procedure is proposed for the kinetic solid-phase spectrophotometric determination of thiocyanate using a polymethacrylate matrix. The procedure is based on the Landolt reaction between Crystal Violet immobilized in a polymethacrylate matrix and a bromate oxidizer, accompanied by the discoloration of the indicator in the matrix. During some induction period after the introduction of thiocyanate into the test solution, the dye in the matrix is not discolored. The duration of the induction period is proportional to the concentration of thiocyanate in the solution. The change in the color of the polymethacrylate matrix was recorded by measuring its absorbance at 600 nm. The developed procedure ensures the determination of thiocyanate in the concentration range 0.025–12 mg/L, depending on the Crystal Violet concentration in the matrix. The limit of detection calculated according to the 3s-test is 0.02 mg/L with the indicator concentration in the matrix of 0.06 mg/g. A possibility of using the proposed procedure for the determination of thiocyanate in near-wellbore water is shown.

Reversible pH-sensitive element based on bromocresol purple immobilized into the polymethacrylate matrix

Reversible pH-sensitive element based on bromocresol purple immobilized into the polymethacrylate matrix was developed. Applications of the pH-sensitive element for continuous monitoring pH of aqueous solution were demonstrated.

Colorimetric Determination of Metal Ions Using Smartphone

The visible sensing determination with color change after solid phase extraction using polymethacrylate matrix and colorimetric smartphone-based technique have been highlighted. The smartphone-based method based on digital photo of transparent polymer optode for metal ions determination is proposed for diapason 0.02-60 mg/L. The optical property of polymer matrix enables a visual color change during its reaction with the analytes. Proposed method is compared with spectrophotometric and colorimetric analysis.