Metal-organic framework as a multi-component sensor for detection of Fe^(3+),ascorbic acid and acid phosphatase

摘要

In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)_(2),was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of Fe^(3+),ascorbic acid(AA) and acid phosphatase(ACP).UiO-66-(OH)_(2) emits yellow-green light under ultraviolet light,when Fe^(3+) was added,Fe^(3+) was chelated with hydroxyl group,the electrons in the excited state S_1 of the MOF transferred to the half-filled 3 d orbits of Fe^(3+),resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation.AA could reduce Fe^(3+) to Fe^(2+),which can destroy the electron transfer between UiO-66-(OH)_(2) and Fe^(3+) after AA adding,resulted in nonoccurrence of the nonradiative electron transfer,leading to the recovery of UiO-66-(OH)_(2) fluorescence intensity.The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid(AAP) to produce AA.Benefitting from the hydroxyl group and the characteristics of UiO-66,including the high porosity and large surface area,the developed UiO-66-(OH)_(2) showed extensive advantages as a fluorescent probe for detection of multi-component,such as high sensitivity and selectivity,colorimetric detection,fast response kinetics and easy to operate,economical and secure.This is the first time to use active group functionalized MOFs as a multicomponent sensor for these three substances detection.