Sponge-Type Emissive Chemosensors for the Protein Detection Based on Boron Ketoiminate-Modifying Hydrogels with Aggregation-Induced Blueshift Emission Property

The construction of the sponge-type chemosensors based on the unique optical properties from the aggregates of the dye-modifying hydrogels is shown herein. Initially, the modified hydrogels involving boron ketoiminate with poly(-glutamic acid) are prepared, and it is confirmed that the synthesized hydrogels can present the aggregation-induced emission (AIE) properties. In particular, it is found that the AIE color is changed by exposing the hydrogels to organic solvents for shrinking the hydrogels. Interestingly, after the treatments with organic solvents, the AIE color of the hydrogel is diverse. This unique behavior can be explained as aggregation-induced blueshift emission. Next, based on this color change in the shrinking, the protein sensing is performed. Finally, it is demonstrated that the color changes of the hydrogels can be significantly induced by the protein solution. This is the first example, to the best of our knowledge, to offer the facile chemosensor for the protein detection based on the unique photophysical process, aggregation-induced blueshift emission.