A team of physicists from the Autonomous University of Madrid (UAM) has managed to improve the characteristics of biosensing nanoparticles made from plasmonic liquid metals, a leading technology useful for early detection of diseases such as cystic fibrosis or cancer. The work has been featured on the cover of Nanotechnology magazine.
Gallium is a liquid metal at room temperature that can be easily combined to form nano-sized particles. Thanks to their good electrical properties and low optical losses, these nanoparticles are able to focus light in their neighborhoods due to the excitation of electrons on the surface. This phenomenon is called plasmon and gives rise to an entire branch of physics known as Plasmonics, with numerous applications in sensors, lasers, photovoltaic technology, etc.
Researchers from the Electronics and Semiconductor Group of the Autonomous University of Madrid have worked in recent years in the application of the plasmonic properties of gallium nanoparticles for the creation of the first biosensors based on this material, capable of detecting, with a large sensitivity, different biomolecules characteristic of rare diseases such as glycogenosis and cystic fibrosis.
Now, these researchers have managed to test a novel procedure with which the optical properties are controlled by the external layer of oxide in gallium nanoparticles. Thanks to this process you can tune the detection range and improve the performance of these devices.
From the chemical modification of its surface, the biosensors based on gallium nanoparticles allow trapping specific markers of a disease in samples of blood, saliva, or tears.
The plasmonic properties of nanoparticles produce changes in the absorption of light proportional to the concentration of biomolecules. Thus, by means of low cost optical systems such as ellipsometry, the concentration of these markers can be identified and quantified, allowing early diagnosis and, at the same time, providing the patient with a daily use tool that will allow him to adjust the doses of the medication and improve their quality of life.