A silica nanoparticle-based dual-responsive ratiometric probe for visualizing hypochlorite and temperature with distinct fluorescence signals

•A silica nanoparticle-based dual-responsive ratiometric fluorescent sensor was synthesized.•The sensor is responsive to ClO− and temperature independently and sensitively.•The detection limit of sensor is 26 nM for ClO−.•The sensor can realize monitoring of ClO− in human serum and live cells.

Hypochlorite (ClO−) and temperature play crucial roles in a wide range of physiological processes, and they are also implicated in various diseases, including cancer, inflammation of tissues and so on. Therefore, it is of great importance to explore a novel method to detect ClO− and temperature instantly. In this study, we developed a silica nanoparticle-based dual-responsive ratiometric fluorescent sensor (DRFS), whose correlative dual emissions can response to ClO− and temperature independently and sensitively. The detection limit of DRFS can reach to as low as 26 nM for the detection of ClO−. And further research demonstrates that DRFS possesses excellent anti-interference feature when other possible interferents exist, and has been successfully applied in ClO− detection in human serum and recognition of exogenous/endogenous ClO− in HeLa cells and macrophages by fluorescence microscopic imaging. Moreover, DRFS can also be used as a ratiometric temperature sensor, and the fluorescence intensity ratio (I576/I445) exhibits a linear temperature response in the range from 20 to 60 °C with a change ratio as large as a factor of 5. Based on the above research, the DRFS can be used as versatile fluorescence sensor in various physiological and environmental systems.

Graphical abstractDownload high-res image (116KB)Download full-size imageA dual-response ratiometric fluorescent biosensor based on silica nanoparticle was synthesized. The sensor exhibited the attractive property of independent dual-response, is not only a ratiometric fluorescent sensor for sensitively and selectively detecting ClO−, but also a ratiometric fluorescence thermometers with good cycling capability towards temperature. More importantly, the detection limit of sensor for detecting ClO− can reach as low as 26 nM, and the sensor has been proved to be a an effective and outstanding fluorescent ClO− sensor in biological system (human serum) and for microscopic cell imaging.