Post-synthetic dual-emission rhodamine B@ZIF-365 hybrid material and Enzymatic Biosensor Enzyme@ZIF-365: Ratiometric temperature sensing, Biomolecule Nicotinamide Detection and Sensing Platform for Lactose and Al3+

Abstract

Through the post-synthetic preparation strategy, Dye molecules Rhodamine B (RhB) and enzyme β-G (β-galactosidase) can be successfully loaded into the zeolite imidazole framework ZIF-365, the unique dual-emission fluorescent hybrid materials RhB@ZIF-365 and MOFs-based enzyme-encapsulated biosensor β-G@ZIF-365 can be prepared. These hybrid materials also have been characterized through PXRD, FT-IR, N2 absorption, thermal stabilities and transmission electron microscope (TEM). Dual-Emission ratiometric fluorescent sensors have the unique advantage, which can avoid the external background influence interference through its self-calibrated detection. In this work, dual-emission RhB@ZIF-365 represents the excellent candidate as the ratiometric MOF-based thermometer with maximum thermometric sensitivity 0.54% °C−1 and good temperature resolution better than 0.1 °C. On the other hand, RhB@ZIF-365 also can be applied as the first example of fluorescent sensor for biomolecule nicotinamide with high sensitivity and selectivity among animo acids. In addition, when enzyme β-G is loaded into ZIF-365 forming the Enzyme-MOF based composite material β-G@ZIF-365, catalytic activity of β-G has been significantly improved. β-G@ZIF-365 can also be used as the first example of fluorescent sensing platform for lactose and Al3+ with high sensitivity and low detection limit 0.14 mM and 1.3 μM, respectively.