Construction And Application Of Glutathione Colorimetric Sensor Based On Fe₃O₄/MIL-88

Glutathione（GSH）,as an important anti-oxidant,could scavenge free radicals in living organisms.Also,it could combine with hazardous materials such as heavy metals to reduce their damage to human body.Therefore,GSH is often used as a bioactive additive in the development of health care food.Moreover,in the field of food industry,GSH can not only prevent the formation of browning by virtue of its redox properties,but also improve the flavor and quality of products.For accurate detection of glutathione in food samples,we synthesized a magnetic metal organic framework,Fe3O4/MIL-88,by the solvothermal method,and established a new GSH colorimetric detection sensor based on the high Fenton-like catalytic activity of Fe3O4/MIL-88.The main results of the study are listed as following:1.Fe₃O₄/MIL-88 composite was synthesized by a solvothermal method.The colloidal stability of Fe₃O₄/MIL-88 detected by ultraviolet spectrometry proves the Fe₃O₄/MIL-88 has good colloidal stability in a short time,which provides a valuable prerequisite for the reliability of future testing.Scanning electron microscope（SEM）image reveals that Fe₃O₄/MIL-88 has a spindle shape with an uniform size of 1.7±0.15μm.The X-ray diffraction（XRD）analysis finds that the Fe3O4/MIL-88 contains all the characteristic diffraction peaks of Fe₃O₄ and MIL-88,fully confirming the successful preparation of Fe₃O₄/MIL-88.2.The Fe₃O₄/MIL-88 composite possesses magnetic property and higher ability to generate·OH over Fe3O4 and Fe-MIL-88,respectively.It is probably because that Fe3O4/MIL-88 exhibits a surprisingly positive synergistic effect on the Fenton-like reaction between Fe₃O₄ and MIL-88,which greatly enhance the Fenton-like catalytic activity of Fe3O4/MIL-88.Experimental results show that trace amount of GSH could greatly facilitate the degradation of MB in the presence of Fe3O4/MIL-88 and H2O2.Considering this,we constructed a highly selective detection sensor for GSH via a turn-off colorimetric process.Under optimal conditions,this sensor has a detection limit of 36.9 nM and good selectivity.This sensor was further applied to the detection of GSH in actual samples（tomato sauce and serum）,and a good recovery was obtained,making this assay a promising tool for the detection of GSH in real samples due to its simplicity,high efficiency and relative-low cost.