Metallic nanoparticles help to determine the percentage of volatile compounds

Metallic nanoparticles, in particular the nanoparticles of

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gold and silver, are widely used in analytical chemistry. Among their applications are optical sensors based on the surface plasmonic resonance in colloidal solutions and on solid supports. Modern optical sensors have considerable advantages like high sensitivity, ease of detecting an analytic signal and adjustability of the optical and laboratory analysis parameters. Nevertheless, these devices have certain limitations when it comes to selectivity.

It happens because of the aggregation of nanoparticles, which happens due to high ionic strength. The ion layer formed on the surface of the particles is called the double electric layer, and is characterized by an electrokinetic potential, also known as the zeta potential. With a decrease in the zeta potential, the electrostatic stabilization of nanoparticles does not happen.

The problem can be solved if the nanoparticles are attached to solid supports; scientists then acquire micro- or nanosensors based on solid particles. There are not many matrix materials for these sensors, and the process of attaching the nanoparticles to supports is complicated, so the researchers started working toward modifying the surface of sensor matrices. For that goal, they proposed separating the nanoparticles from ions and chemical compounds while retaining their sensitivity.

Read more at: https://phys.org/news/2017-10-metallic-nanoparticles-percentage-volatile-compounds.html#jCp