Fast and efficient precision new chemical nano-sensor: can improve the environmental monitoring sensitivity

Recently, Chalmers University of Technology in Sweden has developed a new type of chemical nanosensor, which has benefited from the study of atomic layer thickness nanomaterials, which are extremely sensitive to the surrounding environment.

The sensor is made of transition metal disulfide, a material that interacts strongly with light and is considered a new sensor material and has the ideal specific surface area for thin films. Relevant research results published in Nature Communication.

Ermin Malic of Chalmers University said: "Using our method we can make fast, efficient and accurate sensors that can be used to make highly sensitive and selective sensors for environmental research in the future."

Transition metal disulfides have a wide direct bandgap, easy to generate electron-hole bound excitons when illuminated, and can be used as an efficient sensor material. These excited "bright" excitons are affected by the surrounding environment, so transition metal disulfides can be used to detect the surrounding environment.

The transition metal disulfide also has a light-forbidden "dark" exciton state, and the team found that these "dark" excitonic states turn into "bright" excitons when there are molecules around the dipole moment, and in the spectrum On the formation of a significant additional peak.

According to the team's description, this effect provides an easily identifiable fingerprint for the probe molecule, which is much more efficient than traditional detection methods that rely on small changes in peak positions and changes in intensity.

The team tested the tungsten disulfide, a typical transition metal disulfide material, and found that the phenomenon of optical fingerprinting was indeed related to the number of dipole molecules covered by the sensor material.

With the increase of the dipole molecular coverage, the peak corresponding to the dark exciton transforms into the corresponding peak corresponding to the bright exciton, and the peak position shifts from the higher energy side to the lower energy side. This effect can be used to directly detect the distribution of dark excitons, and vice versa to detect the distribution of the corresponding dipole molecules.

Maja Feierabend of Chalmers University said: "This effect provides new insights into the air environment and our approach is more efficient than traditional sensors that rely on changes in small optical properties."