A team led by Sun Xiaolong from the School of Life Science and Technology at Xi'an Jiaotong University has developed a new chemical reaction system that represents a breakthrough in dynamic chemical covalent bond visualization.

Sun's team has long been committed to the design, development and application of functional molecules. Based on the precise synthesis of molecules, through principle and technological innovation, new chemical reactions have been developed to construct specific functional materials.

This study has dual significance. One is to realize the real-time observation and tracking of the covalent bonding process of soft matter materials during gelation, structural remodeling and chemical degradation, and establish the response relationship between the time changes of optical mechanics. 

Another is to realize the dual functions of material degradation and analyze detection visualization through chemically triggered gel decomposition and optical signal self-amplification cyclic amplification systems.

The researchers developed a new photoluminophore called indanoneene to construct a photoluminescence platform. Through the chemical exchange of thio-amine groups, the fluorescence changes of optical reactions between a conjugated receptor and amine compounds can be tracked and quantified, making it possible to develop a new generation of smart materials.

Photoluminescence platform builds and enables fluorescence visualization of hydrogel polymer synthesis, remodeling and degradation.

Fluorescence-enhanced visualization and tracking of hydrogel synthesis, remodeling, and degradation

The researchers also developed a single-conjugated acceptor indanoneene luminophore, whose photochemical reaction with β-mercaptoethanol under neutral conditions yielded ratiometric absorption and fluorescence-on-signal changes.

On this basis, polyethylene glycol hydrogels containing non-luminescent conjugated acceptor linkers were synthesized via a CuAAC click reaction, and then synergized with 2-hydroxyethyl disulfide to form a thiol-triggered self-circulation, which realizes the dual signal response of fluorescence signal amplification and macromolecular material degradation.

It can be used to develop biosensors with high sensitivity and selectivity, especially for early diagnostic detection.

Thiol-triggered hydrogel self-circulating cascade fluorescence signal amplification system and its application in the visual detection of thiol compounds

The research results were published in Journal of the American Chemical Society and Polymer Chemistry. Doctoral student Wu Tianhong and master’s student Feng Xing participated in the research. Sun is the only corresponding author and the Key Laboratory of Biomedical Information Engineering of the Ministry of Education is the only corresponding unit.

The research was financed by the National Natural Science Foundation of China.

Link to the paper: 

https://pubs.acs.org/doi/10.1021/jacs.1c09895

https://doi.org/10.1039/D1PY01450A