锰/锆-双金属有机骨架纳米酶比色法检测水中痕量氟

Colorimetric Detection of Trace Fluoride in Water Based on Manganese/Zirconium Bimetallic Organic Framework Nanoenzyme

该文设计合成了一种新型锰/锆-双金属有机框架(Mn/Zr-MOF)纳米材料,并用于水中痕量氟的检测。顺磁性金属锰、锆赋予了Mn/Zr-MOF类过氧化物酶活性,而锆金属能选择性识别氟离子(F^(-))。Mn/Zr-MOF可催化过氧化氢氧化3,3',5,5'-四甲基联苯胺(TMB)生成蓝色oxTMB,其最大吸收波长为652 nm。体系中的F^(-)可与锆特异性结合,并抑制Mn/Zr-MOF的催化活性,使体系颜色变浅。F^(-)质量浓度与652 nm处的吸光度呈负相关关系,据此建立了一种检测F^(-)的比色法。方法的线性范围为0.40~5.0 mg/L,检出限为0.16 mg/L。将该方法应用于实际水样中F^(-)测定,加标回收率为97.6%~106%,相对标准偏差为0.27%~5.2%。该方法快速、灵敏、选择性好,在实际样品分析中具有较大潜力。

In this paper,a new manganese/zirconium bimetallic organic framework(Mn/Zr-MOF)nanomaterial was designed and synthesized.Paramagnetic metal manganese and zirconium endow Mn/Zr-MOF with peroxidase-like activity,while zirconium can selectively recognize fluoride ion(F^(-)).Mn/Zr-MOF nanomaterial exhibits excellent peroxidase-like activity.It can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)with hydrogen peroxide to generate blue oxTMB,with a maximum absorption wavelength of 652 nm.If F^(-)exists in the system,it can selectively bind with Zr and exerts inhibitory effect the catalytic activity of Mn/Zr-MOF,resulting in a lighter color in the system.The concentration of F^(-)was negatively correlated with the absorbance at 652 nm,thus a colorimetric method for F^(-)detecting was established.The linear range of the method was 0.40-5.0 mg/L,and the detection limit was 0.16 mg/L.The method was applied to the determination of F^(-)in actual water samples,with recovery of 97.6%-106%and relative standard deviation of 0.27%-5.2%.The proposed method is fast,sensitive,and highly selective,holding great potential in actual sample analysis.