The monitoring of reactive oxygen species (ROS) in living cells remains challenging because of the complexity, short half-life, and autofluorescence of biological samples. In this work, we designed a ratiometric fluorescent probe for the detection and imaging of ROS, which was constructed from silicon quantum dots (Si QDs) with chlorin e6 (Ce6) through electrostatic attraction and showed well-resolved dual fluorescence emission signals (490 and 660 nm). Sensitive and selective biosensing of hydroxyl radical (•OH) was demonstrated on the basis of fluorescence quenching of the Si QDs and Ce6 as an internal reference to avoid environmental interference, with a detection limit of ∼0.97 μM. The endogenous release of •OH was also monitored and imaged in living cells.Keywords: cell imaging; chlorin e6 (Ce6); highly reactive oxygen species; hydroxyl radical (•OH); ratiometric fluorescence probe; silicon quantum dots;

Naproxen–β-cyclodextrin inclusion complex was prepared by the freeze-drying method and analyzed by IR, UV spectroscopy, X-ray diffractometry and differential scanning calorimetry. Phase solubility, dissolution and inclusion rate of the complex were determined. The phase solubility diagram was of the AL type, which revealed that the molar ratio of naproxen to β-cyclodextrin was 1:1. The solubility of naproxen significantly increased with increasing β-cyclodextrin concentration. The apparent stability constant, Kc, was calculated from the slope and intercept of the AL solubility diagram as 2376/M. The total released amount and released time of naproxen from the inclusion complex were better than that of the intact naproxen.