A fluorescence digital image-based method using carbon quantum dots to evaluate the compliance of a biocidal agent

Abstract

In this work, a simple, low-cost and easy-to-handle analytical procedure based on carbon quantum dots (CQDs) is proposed to check commercially available formulated microbicides that is used to mitigate the...

Using a cotton thread-based colorimetric sensor modified by carboxymethylcellulose and cuprizone with smartphone detection for quantification of copper

“…The use of the flashlight from a smartphone camera to illuminate the chamber helps minimize the undesirable effects of shadow or reflection caused by external light. 38–40 A uniform region of the ROI image with 10 × 50 pixels was decomposed to obtain the RGB values using the Color Grab application. Considering the complexation of cupric ions with CPZ, CPZ-Cu exhibited a blue color, so the channel that was found to provide the best response was the red (R) channel from the RGB model.…”

“…38 Considering that the detection technique is based on reflectance signals, the color change in the cotton thread is correlated with the analyte concentration. 39–41…”

Using a biphasic system and digital imaging analysis with chemometric tools for simultaneous determination of Cu2+ and furfural in cachaça

“…26 The use of digital images provides the opportunity to perform rapid and direct analytical quantications and determinations; in particular, the combination of digital images with colorimetric techniques; i.e., digital image-based (DIB) or uorescence digital image-based (FDIB) methods allows one to perform a wide range of analyses in several different areas of application. 28,[30][31][32] For applications involving DIB and FDIB techniques, one needs to employ support platforms; the materials commonly used for the construction of these platforms include paper, 12 ceramic plates, 33 polystyrene microplates, 28 and polylactic acid, 32 to name a few. When it comes to the analysis aimed at determining the concentration of analytes of interest, care must be taken regarding the control of luminosity of the analytical platform.…”

“…34 In view of that, it is essentially important to use closed chambers during the analysis in order to avoid this analytical inconvenience. 12,28,32,33 Two-phase systems in thermodynamic equilibrium are commonly employed in many applications. 35,36 The chemical nature of the phase-forming components has a strong impact on the interfacial properties of two-phase systems; moreover, apart from inuencing the solute partition coefficient, the interfacial tension affects other properties of the system, including kinetic and thermodynamic stability of dispersion, kinetics of partition, etc.…”

“…34 In view of that, it is essentially important to use closed chambers during the analysis in order to avoid this analytical inconvenience. 12,28,32,33…”