Salicylideneanilines encapsulated mesoporous silica functionalized gold nanoparticles: a low temperature calibrated fluorescent thermometer

Abstract

In this study, a novel temperature responsive fluorescent sensor, 4-(2-hydroxybenzylideneamino)benzoic acid (HBA), encapsulated in the nanochannels of mesoporous silica functionalized with gold nanoparticles (GMS) was synthesized and studied. The fluorescence intensity of HBA–GMS showed excellent linear temperature sensitivity over a wide range, from cryogenic to room temperature (100–298 K). Meanwhile, GMS was used as an immobilization matrix to improve light harvesting and calibrate the HBA fluorescence intensity at different temperatures because of the stable and insensitive fluorescence signal of the gold nanoparticle intercalated into the walls of GMS. In addition, it was found that HBA–GMS exhibits excellent biocompatibility and low toxicity for cellular imaging due to the robust GMS support. These results suggest that the assembled mesostructure provides a promising, intelligent, and calibrated fluorescent thermometer with potential applications as a sensor and in cryogenic bio-detection and therapy fields.