Design and Preparation of Phosphorescent Lifetime-Responsive Polymeric Probes for Enzyme Targeting and Catalytic Activity Sensing in Living Cells

Project: Research

View graph of relations



This project aims to develop novel strategies to study the activity of enzymes in live cells by making use of: 1) amphiphilic peptides and polymers, and 2) phosphorogenic bioorthogonal probes derived from transition metal complexes. Enzymes are responsible for numerous important cellular processes and play central roles in a number of diseases and conditions. Thus, probes that reveal the activity of enzymes in live cells are urgently required. The existing methods for the detection of enzyme activity have limitations such as poor spatial distribution accuracy, low reproducibility, and susceptibility to the complex microenvironment in live cells. In this project, we will utilize specially designed peptide- and polymer-based amphiphiles, intriguing photophysical characteristics of transition metal complexes, and specific bioorthogonal reactions to develop two innovative strategies for imaging enzyme activity in live cells. In the first strategy, sensing and imaging will reply on enzyme-induced morphological transformation of spherical micelles of a hydrophobic core–hydrophilic shell structure to expose an embedded chemical reporter. The exposed chemical reporter will then undergo a specific bioorthogonal reaction with our proposed transition metal complexes, producing a phosphorogenic response for detection. In the second strategy, the chemical reporter is caged with a peptide-based enzyme substrate and a hydrophilic oligopeptide. Upon enzyme-catalyzed cleavage of the substrate, the released chemical reporter can gain access to the hydrophobic core of the micelles and react with the embedded phosphorogenic bioorthogonal probes. In both strategies, the resulting emission turn-on of the transition metal complexes can be readily monitored by photophysical measurements and laser-scanning confocal microscopy techniques. Additionally, due to the long-lived phosphorescence nature of our target transition metal complexes after the bioorthogonal reaction, time-resolved detection and phosphorescence lifetime imaging microscopy (PLIM) will be exploited, which will significantly enhance the sensitivity, reliability, and accuracy of the detection and imaging of enzyme activity in live cells. We believe that the utilization of these interesting peptide- and polymer-based amphiphiles and phosphorogenic bioorthogonal probes derived from transition metal complexes will further enhance the capability, significance, and diversity of bioanalytical probes and imaging reagents. We are confident that the outcomes of this project will not only provide new and exciting research results, but also bring enormous impact such as the training and career development of research personnel, deliver new knowledge and information to the general public, and produce innovative diagnostic and therapeutic reagents that will greatly benefit patients suffering from enzyme-related diseases and conditions.


Project number9054037
Grant typeNSFC
Effective start/end date1/01/22 → …