ABSTRACT
In the present approach, a Cr2O3-TiO2-modified, portable, and biomimetic nanosensor was designed to meet the requirement of a robust and colorimetric sensing of hydrogen peroxide. Cr2O3-TiO2 nanocomposites prepared via the hydrothermal method were fabricated as a transducer surface on the filter paper using the sol-gel matrix. The color on the filter paper sensor changed from green to blue upon the addition of hydrogen peroxide in the presence of TMB. This change in the color intensity was linear with the concentration of H2O2. RGB software was used as a color analyzing model to evaluate the optical signals. This paper-based colorimetric platform provided us with an improved analytical figure of merit with a linear range of 0.005-100 µM with 0.003 µM limit of detection. The real sample analysis and excellent anti-interference potential results proved the good analytical performance of the proposed design, providing a more promising tool for colorimetric H2O2 detection. Introducing Cr2O3-TiO2 nanocomposite-based paper sensors, being a novel method for optical and colorimetric detection, can pave the way for the development of other sensing devices for the detection of different analytes.
ABSTRACT
The present work was focused to design a cheap, rapid, portable and easy to use filter paper based assay for the qualitative and quantitate analysis of acetone. Sodium alginate gel was loaded with the acetone specific optical signal probe, and subsequently coated onto filter paper surface to design portable colorimetric assays for acetone monitoring. The color of the paper sensor strip was observed to change from dark yellow to light yellowish in the presence of varying concentrations of acetone. Three different color analyzing models including RGB, HSV, and LAB were employed to probe the output optical signal, and their performance was compared in terms of better interpretation of the generated signal. The LAB model was found to provide better analytical figures of merit with a linear response for the acetone concentration ranging from 2.5 to 1500 ppm, and a limit of detection of 0.5 ppm. Furthermore, the specificity of the designed filter paper based sensor was demonstrated against different common interfering compounds. The results demonstrated the potential of our proposed filter paper based sensor as a novel tool for the analysis of acetone.
