Chinese scholars have made important breakthroughs in the research of ultra-small and high-performance luminescent nanoparticles

An important breakthrough has been made in the field of nano-luminescent materials
.
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China News Service, Harbin, September 15 (Reporter Yifu Shi) Heilongjiang University announced on the 15th that the research team led by Professor Xu Hui of the school and Professor Liu Xiaogang of the National University of Singapore has made important breakthroughs in the field of nano-luminescent materials, which is the first international proof The long-distance (about 5 nanometers) regulation effect of ligands on the luminescence properties of nanoparticles is revealed, and the mechanism of surface electronic state reconstruction of nanoparticles based on the coordination field action is revealed, which provides for the construction of hybrid nano-luminescent materials based on ligand engineering.
The key theoretical basis and brand-new ideas are presented
.

Ultra-small rare-earth-doped nano-luminescent particles have the advantages of high luminous color purity, multiple bands, wide range, high stability, etc.
, and have very important applications in the fields of super-resolution display, remote diagnosis and treatment, and biomarking
.

Small-sized nanoparticles often suffer severe surface quenching, which limits the application of such materials in low-concentration and high-resolution environments
.
It is generally believed that organic ligands on the surface of particles can inhibit surface quenching by means of physical barriers

This recognition greatly limits the development of organic-inorganic composite nano-optical systems with excellent luminescent properties from the perspective of ligand functionalization
.
Therefore, the research on the surface quenching mechanism of such nanomaterials has extremely important theoretical significance

The team found that through organic ligands with special coordination modes, long-range field effects can be formed on the surface of nanoparticles, thereby activating the quenched luminescent ions on the surface, optimizing the energy transfer process in the nanoparticles, thereby greatly enhancing upconversion luminescence
.

This effect can increase the luminous intensity of nanoparticles within 10 nanometers by more than 3000 times
.
This result indicates that the ligand has a significant regulatory effect on the electronic state of the nanoparticle surface, overturning the traditional understanding that only considers the physical barrier effect of the ligand, forming a comprehensive understanding of the role of the ligand, the combination of the local and the whole, and it is an ultra-small nano The application of particles in biology, display, anti-counterfeiting and detection has laid a solid theoretical foundation in many important fields of national science, technology and economy