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Microfluidics is well-known for many Lab-on-a-Chip applications including sensing, cell sorting, separation, chemical reaction, emulsification, de-emulsification, droplet generation, energy generation and similar applications. The current research scenario in the field of interfacial science and colloidal technology has facilitated the advancement of microfluidics as a miniaturized option for many targeted tasks. Here we show how the microfluidics offers a low-cost solution for concentrating the dispersion of magnetic nanoparticles. The synthesized nanofluids were fed to the microchannels subjected to magnetic field. It has been found that the feed flow rate is one of the very crucial factors which affect the control of concentration of the nanofluids. [ABSTRACT FROM AUTHOR]

This paper reports an ingenious colorimetric sensor probe for the detection of Cd2+ ions using cysteamine functionalized gold nanoparticles cross-linked with DL-glyceraldehyde (DL-G-CA-Au NPs). Rapid aggregation in DL-G-CA-Au NPs was observed by adding Cd2+ ions at PBS buffer pH 7.0, which results in an immediate color change of the solution from red to blue. A red-shift in the wavelength of absorption peak was measured from 520 to 736 nm using UV-visible spectroscopy. The surface functionalization and aggregation of Au NPs were also characterized by recoding FI-IR and DSL data. The colorimetric probe was analyzed in the concentration of Cd2+ ions ranging from 0.05 to 500 μM, and a good linearity was observed towards the lower concentration levels with a coefficient of correlation R2 = 0.9862. The limit of detection was found to be 21 nM, which best describes its superior performance over other reported colorimetric probes. Furthermore, the performance of the probe was not influenced by other metal ions, and the stability of DL-G-CA-Au NPs was maintained even after 30 days. The proposed method was successfully applied to various water samples collected from the environment, and an accuracy ≥ 98% was achieved. [ABSTRACT FROM AUTHOR]

Proteins are very important biological macromolecules, specific in their functions essential for many biological activities. Proteins are among the most vital components of all living matters with thousands of different types, and they are very specific in their nature which makes them important for usage in many biotechnological, biomedical, and food processing applications. Langmuir monolayer studies provide the characteristics of monolayer at the air-liquid interface. Langmuir monolayer of protein is affected by the molecular weight, macromolecular structure, denaturation and its purity. The interaction of the protein with other molecules greatly affects the behaviour of monolayer. Coconut oil layer at the air-water interface was prepared with different sub-phases including casein protein and whey protein. Wilhelmy plate measurement technique has been used to measure the surface pressure of the monolayer at the air-liquid interface. Experiments were carried out to study the stability using electrochemical impedance measurements. The electrostatic forces dominated the coconut oil - protein interaction, and the interface of macromolecules were controlled by expansion and compression. The macromolecules were adsorbed with a preferential orientation at the interface, and the stability of colloidal dispersions was governed by the intermolecular interactions. The stability using electrochemical impedance spectroscopy on the selected protein macromolecules along with other analysis were performed by varying various parameters., (Copyright © 2019 Elsevier B.V. All rights reserved.)