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.

Visual determination of malachite green in sea fish samples.

Polymethylmethacrylate matrix has been developed as an analytical device for visual and spectrophotometric determination of malachite green. Based on the studied effects of different pH levels, temperature, contact time and diverse ions, optimum analysis conditions have been established. For malachite green, the calibration graph was linear in the range of 0.5-30 mg·L-1 in the samples with the detection limit of 1 mg·kg-1. The proposed simple method makes it possible to determine malachite green visually in the concentration range 8-30 mg·L-1 using a colour scale. The method has been implemented for determination of malachite green in various sea fish samples.