Scientists at Far Eastern Federal University (FFU), with colleagues from Russia, Japan and Australia, have developed a multi-purpose sensor that identifies trace amounts of liquid and gas molecules. The sensor comprises a specially formulated gold film whose surface contains millions of parabolic nanoantennas produced by femtosecond laser printing. The research is published in Nanomaterials.
The sensor reacts to tiny changes in its surroundings in close proximity to its surface, e.g. gas or organic molecules, changes in the local refractive index of a liquid, etc. It can be used for bioanalysis, environmental monitoring, food quality analysis, and various security systems.
"Despite the significant progress that science has made in the field of high-precision physicochemical sensors over the past several decades, flexible inexpensive technologies for manufacturing cheap multi-purpose sensors combining different measurement modalities within a single device are still required," said Aleksandr Kuchmizhak, research fellow at the FEFU STI for Virtual and Augmented Reality, in a statement. “Existing lithographic technologies for such sensors fabrication are time and money consuming and therefore are not suitable for mass production. We proposed efficient and cheap laser printing technology to solve the mentioned issue.“
The nanotextured gold film sensor is fabricated by direct femtosecond-laser printing. Exposing the ultrathin gold film to single femtosecond pulses results in formation of millions of hollow parabolic nanostructures (nanovoids), the so-called nanoantennas. The nanostructure array effectively converts incident visible and IR radiation into special surface waves, so-called surface plasmons, which make the sensor highly sensitive to changes in the surroundings.
Scientists from FFU, FEB RAS and MEPhI, as well as from Nagoya Institute of Technology (Japan), Tokai University (Japan) and Swinburne University of Technology (Australia) took part in the work.