Ce-MOF材料的合成及其在抗坏血酸检测中的应用

Synthesis of Ce-MOF and its application in ascorbic acid detection

本文以对苯二甲酸(H_(2)BDC)和硝酸铈铵(Ce(NH_(4))_(2)(NO_(3))_(6))为原料合成了具有UIO-66结构的铈基金属有机框架(Ce-MOF)材料。该Ce-MOF可模拟氧化酶活性催化3,3′,5,5′-四甲基联苯胺(TMB)氧化生成蓝色的氧化产物(oxTMB),同时在650 nm处出现特征吸收峰。抗坏血酸(AA)能够抑制生成oxTMB的氧化反应,从而使体系蓝色减弱,且650 nm处的吸光度随着AA的浓度增加而降低。实验结果显示,在优化后的pH条件下,显色体系在650 nm处的吸光度与AA浓度在0.01~0.6 mmol/L范围内呈现出良好的线性关系,检出限低至0.007 mmol/L,可用于AA的低成本、高灵敏和快速检测。

In this work,Ce-based metal-organic framework(Ce-MOF)with UIO-66 structure was synthesized from terephthalic acid(H _(2) BDC)and cerium(IV)ammonium nitrate(Ce(NH _(4))_(2)(NO _(3))_(6)).The Ce-MOF can catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine(TMB)to oxidation product(oxTMB)with blue color and characteristic absorption peak at 650 nm.Ascorbic acid(AA)can inhibit the oxidation reaction to produce oxTMB,which weakens the blue color of the system,and the absorbance at 650 nm decreases with the increase of AA concentration.Under optimized pH conditions,the absorbance at 650 nm of the sensing system exhibited good linear relationship with AA concentration during the range of 0.01-0.6 mmol/L,and the detection limit was as low as 0.007 mmol/L.Thus,the developed sensing system consist of Ce-MOF and TMB could be used for the low-cost,highly sensitive and rapid detection of AA.