Core-shell structured phosphorescent nanoparticles for detection of exogenous and endogenous hypochlorite in live cells via ratiometric imaging and photoluminescence lifetime imaging microscopyElectronic supplementary information (ESI) available: Experimental procedures, characterisation data, Scheme S1 and Fig. S1-S3. See DOI: 10.1039/c4sc02600d

• Main Authors: Zhang, Kenneth Yin, Zhang, Jie, Liu, Yahong, Liu, Shujuan, Zhang, Pinglin, Zhao, Qiang, Tang, Yan, Huang, Wei
• Format: Article
• Language: English
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c4sc02600d

We report a ratiometric phosphorescence sensory system for hypochlorite (ClO − ) based on core-shell structured silica nanoparticles. Two phosphorescent iridium( iii ) complexes were immobilised in the inner solid core and outer mesoporous layer of the nanoparticles, respectively. The former is insensitive to ClO − and thus serves as an internal standard to increase the accuracy and precision, while the latter exhibits a specific and significant luminogenic response to ClO − , providing high selectivity and sensitivity. Upon exposure to ClO − , the nanoparticles display a sharp luminescence colour change from blue to red. Additionally, intracellular detection of exogenous and endogenous ClO − has been demonstrated via ratiometric imaging and photoluminescence lifetime imaging microscopy. Compared to intensity-based sensing, ratiometric and lifetime-based measurements are independent of the probe concentration and are thus less affected by external influences, especially in intracellular applications. Core-shell phosphorescent nanoparticles were used to detect intracellular ClO − via ratiometric and photoluminescence lifetime imaging.