"Switch-On" Fluorescence Detection of Glucose with High Specificity and Sensitivity Based on Silver Nanoparticles Supported on Porphyrin Metal-Organic Frameworks.

As the energy source of living cells and the intermediate product of metabolism, glucose plays an important role in biological systems. Therefore, it is of great significance to establish a reliable and sensitive method for the detection of glucose, especially in blood. Herein, a "switch-on" fluorescence sensor for rapid, sensitive, and specific detection of glucose was successfully developed. In this strategy, PCN-224 served as the recognition unit, while AgNPs played the roles as both a "quencher", to decrease the fluorescence intensity of PCN-224, and an H2O2 recognizer. After exposure to H2O2 that was produced in situ during GOx-catalyzed oxidation of glucose, AgNPs can be effectively etched into silver ions and released from PCN-224, thereby recovering the fluorescence of PCN-224. The present sensing strategy shows many merits including high sensitivity with a low limit of detection (0.078 μM) and excellent selectivity toward glucose over other saccharides. More importantly, the sensing platform we proposed was further extended to monitoring glucose in human serum samples with satisfactory recoveries, indicating its promising potential for diagnostic purposes.