Preparation and application of peptide molecular imprinted material based on mesoporous metal-organic framework

Fig.2 XRD patterns of (a) simulated UiO-66-NH2, (b)microporous UiO-66-NH2, (c)mesoporous UiO-66-NH2 and (d) mesoporous MIP@UiO-66-NH2. Fig.3 SEM images of (a)microporous UiO-66-NH2, (b) mesoporous UiO-66-NH2 and (c) mesoporous MIP@UiO-66-NH2; TEM images of (d) microporous UiO-66-NH2 (e) mesoporous UiO-66-NH2 and (f) mesoporous MIP@UiO-66-NH2 Fig.4 N2 sorption isotherms of (a) UiO-66-NH2 (b) UiO-66-NH2 after decarboxylation (c) mesoporous MIP@UiO-66-NH2 and pore sizes distribution of (d) UiO-66-NH2 (e) UiO-66-NH2 after decarboxylation (f) mesoporous MIP@UiO-66-NH2 Fig.5 The effects of pore size and dosage of MOFs on the adsorption capacity of [e-mail] conditions: mGSH=100 mg, mAM=0.72 g, mNVP=0.56 g, mNMBA=10 mg, and mDMDAAC=0.14 g; adsorption conditions:cGSH,0=0.1 g·L-1, V=1 mL, mMIP=1 mg, t=4 h, pH=7.00, T=4 ℃; eluent : CH3OH/HAc (9/1, v/v) Fig.6 The effect of the ratio of cross-linking agents and functional monomers on the adsorption capacity of [e-mail] conditions: mGSH=100 mg, mmesoporous UiO-66-NH2=100 mg, other conditions see Fig.5 Fig.7 The effect of eluent on the adsorption capacity of MIP@UiO-66-NH2. Polymerization conditions: mGSH=100 mg, mmesoporous UiO-66-NH2=100 mg, mAM=0.72 g, mNVP=0.56 g, mNMBA=2 mg, mDMDAAC=0.028 g; other conditions see Fig.5 Fig.8 (a)Adsorption isotherm, (b) the Langmuir model, (c) the Freundlich model of [e-mail] conditions see Fig.5; polymerization conditions see fig.7, eluent: 1% SDS/10% HAc (w/v) Fig.9 Kinetic adsorption curves and kinetic model fitting curves of (a) Pseudo-first order model and (b) Pseudo-second order model of MIP@UiO-66-NH2 at different temperatures. Adsorption conditions: t=1, 2, 5, 10, 20, 30, 40, 50, 60, 120 min, T=4℃, 25℃, 37℃, other conditions see Fig.5; polymerization conditions see Fig.7; eluent:1% SDS/10% HAc (w/v) Fig.10 The MALDI-TOF mass spectra:(a) the remaining solution after adsorption (the loading condition: 0.10 g·L-1of GSH and 0.10 g·L-1 BSA tryptic digest) (b) the obtained eluent, (c) the remaining solution after adsorption (the loading condition:0.10 g·L-1 of GSH and 1.0 g·L-1 BSA tryptic digest),(d) the obtained eluent (★indicates GSH) Fig.11 The MALDI-TOF mass spectra:(a) the remaining solution after adsorption (the loading condition: 500 μL 0.10 g·L-1of GSH and 500 μL skim milk tryptic digest) (b) the obtained eluent, (c) the remaining solution after adsorption (the loading condition: 500 μL 0.10 g·L-1of GSH and 500 μL egg white tryptic digest),(d) the obtained eluent (★indicates GSH)

图2 为（a）模拟UiO-66-NH₂、（b）微孔UiO-66-NH₂、（c）介孔UiO-66-NH₂及（d）介孔分子印迹聚合物@UiO-66-NH₂的X射线衍射（X-ray Diffraction, XRD）图谱。图3 为（a）微孔UiO-66-NH₂、（b）介孔UiO-66-NH₂及（c）介孔MIP@UiO-66-NH₂的扫描电子显微镜（Scanning Electron Microscope, SEM）图像；以及（d）微孔UiO-66-NH₂、（e）介孔UiO-66-NH₂和（f）介孔MIP@UiO-66-NH₂的透射电子显微镜（Transmission Electron Microscope, TEM）图像。图4 为（a）UiO-66-NH₂、（b）脱羧后的UiO-66-NH₂、（c）介孔MIP@UiO-66-NH₂的氮气吸附等温线，以及（d）UiO-66-NH₂、（e）脱羧后的UiO-66-NH₂、（f）介孔MIP@UiO-66-NH₂的孔径分布。图5 考察了孔径与金属有机框架材料（Metal-Organic Frameworks, MOFs）用量对MIP@UiO-66-NH₂吸附容量的影响。聚合条件：谷胱甘肽（Glutathione, GSH）质量$m_{GSH}$=100 mg，丙烯酰胺（Acrylamide, AM）质量$m_{AM}$=0.72 g，N-乙烯基吡咯烷酮（N-Vinylpyrrolidone, NVP）质量$m_{NVP}$=0.56 g，N,N'-亚甲基双丙烯酰胺（N,N'-Methylenebisacrylamide, NMBA）质量$m_{NMBA}$=10 mg，二甲基二烯丙基氯化铵（Dimethyldiallylammonium Chloride, DMDAAC）质量$m_{DMDAAC}$=0.14 g；吸附条件：初始谷胱甘肽浓度$c_{GSH,0}$=0.1 g·L⁻¹，体系体积$V$=1 mL，吸附剂用量$m_{MIP}$=1 mg，吸附时间$t$=4 h，pH=7.00，温度$T$=4 ℃；洗脱剂为甲醇/乙酸（CH₃OH/HAc，体积比9/1）。图6 考察了交联剂与功能单体配比对MIP@UiO-66-NH₂吸附容量的影响。聚合条件：$m_{GSH}$=100 mg，介孔UiO-66-NH₂质量$m_{mesoporous UiO-66-NH2}$=100 mg，其余条件同图5。图7 考察了洗脱剂对MIP@UiO-66-NH₂吸附容量的影响。聚合条件：$m_{GSH}$=100 mg，$m_{mesoporous UiO-66-NH2}$=100 mg，$m_{AM}$=0.72 g，$m_{NVP}$=0.56 g，$m_{NMBA}$=2 mg，$m_{DMDAAC}$=0.028 g；其余条件同图5。图8 为MIP@UiO-66-NH₂的（a）吸附等温线、（b）朗缪尔（Langmuir）模型拟合曲线及（c）弗罗因德利希（Freundlich）模型拟合曲线。吸附条件同图5；聚合条件同图7，洗脱剂为1%十二烷基硫酸钠（Sodium Dodecyl Sulfate, SDS）/10%乙酸（w/v）。图9 为不同温度下MIP@UiO-66-NH₂的（a）准一级动力学模型及（b）准二级动力学模型的吸附动力学曲线与动力学模型拟合曲线。吸附条件：吸附时间$t$依次为1、2、5、10、20、30、40、50、60、120 min，温度$T$分别为4 ℃、25 ℃、37 ℃，其余条件同图5；聚合条件同图7；洗脱剂为1% SDS/10%乙酸（w/v）。图10 为基质辅助激光解吸电离飞行时间质谱（Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry, MALDI-TOF MS）图谱：（a）吸附后的残留溶液（上样条件：0.10 g·L⁻¹谷胱甘肽与0.10 g·L⁻¹牛血清白蛋白（Bovine Serum Albumin, BSA）胰酶消化液）、（b）所得洗脱液、（c）吸附后的残留溶液（上样条件：0.10 g·L⁻¹谷胱甘肽与1.0 g·L⁻¹ BSA胰酶消化液）、（d）所得洗脱液（★代表谷胱甘肽）。图11 为MALDI-TOF MS图谱：（a）吸附后的残留溶液（上样条件：500 μL 0.10 g·L⁻¹谷胱甘肽与500 μL脱脂奶胰酶消化液）、（b）所得洗脱液、（c）吸附后的残留溶液（上样条件：500 μL 0.10 g·L⁻¹谷胱甘肽与500 μL蛋清胰酶消化液）、（d）所得洗脱液（★代表谷胱甘肽）。