孕酮分子印迹表面等离子共振传感器的制备

以孕酮为模板分子,甲基丙烯酸为单体,乙二醇二甲基丙烯酸酯为交联剂,二苯甲酮为光引发剂,通过现场光接枝的方法合成孕酮分子印迹膜(MIF)。原子力显微镜结果显示,MIF表面分布许多纳米尺寸的用于吸附模板分子的孔穴;采用表面等离子共振技术对1.0～1.0×10~3pmol/L的孕酮进行吸附检测,光强增加值与孕酮浓度的对数值间呈线性关系,检出限为0.3 pmol/L。7次洗脱-重新吸附后,MIF仍具有较好的传感性能,放置90 d后,孕酮分子印迹膜仍能进行很好洗脱和吸附。此分子印迹膜传感器用于人工尿液中检测孕酮,回收率在96.0%～102.5%之间。     

三聚氰胺分子印迹表面等离子体共振传感器的制备及分析应用

以合成的烯丙基-1,3,5-三嗪-2,4,6-(1H,3H,5H)三酮为功能单体,三聚氰胺为模板分子,乙二醇二甲基丙烯酸酯为交联剂,在表面等离子体共振(SPR)传感芯片上合成了分子印迹聚合物薄膜。根据印迹聚合物的朗格缪尔方程式,计算得到三聚氰胺和分子印迹聚合物之间的结合常数为1.40×10~8L/mol。此传感器显示出对模板分子三聚氰胺的高选择性,在p H=7.5的条件下,此传感器对三聚氰胺的响应最佳,线性范围为0.1-10.0 nmol/L(R=0.9991)。将此传感器用于牛奶和奶粉中三聚氰胺的检测,检出限分别为62.6 pmol/L和56.4 pmol/L(S/N=3),回收率分别为91.5%和92.0%。     

孔雀石绿分子印迹表面等离子共振传感器的制备及分析应用

利用表面等离子共振(SPR)光谱,结合分子印迹技术,制备了孔雀石绿分子印迹SPR传感器,建立了检测孔雀石绿的分析方法。探讨了pH值对分子印迹膜吸附特性的影响,并在最佳pH下对其吸附选择性进行了考察。研究结果表明,与相应非印迹传感膜相比,孔雀石绿印迹传感膜对孔雀石绿具有较高的吸附选择性能。该方法测定河水及河泥中孔雀绿的线性范围为8.0×10-10~1.0×10-8 mol/L,检出限(S/N=3)分别为8.83×10-11 mol/L和1.55×10-10 mol/L,平均回收率分别为91.97%和93.88%,相对标准偏差分别为1.2%和2.1%。该方法具有简单、快速、灵敏度高、重复性好等特点,适用于河水和河泥中孔雀石绿的测定。     

苏丹红Ⅰ印迹表面等离子共振传感器的制备与表征

以苏丹红I印迹的凝胶膜对模板分子的响应收缩为基础,利用表面引发聚合技术在表面等离子共振（SPR）芯片上制备了苏丹红I印迹SPR传感器,利用电化学和溶胀测量技术对传感器进行表征,建立了对苏丹红I的SPR检测方法。该方法的线性范围为8.0×10-10~1.0×10-8 mol/L(R2=0.9987)。 方法用于样品红辣椒粉和腌制品中苏丹红I的检测,其检出限分别为3.4×10-10和2.5×10-10 mol/L。 红辣椒粉中两个样品的相对标准偏差为1.38%和2.10%,腌制品试样的相对标准偏差为1.13%。 说明该方法具有较高的灵敏度和较好的的重现性。     

SiO2介孔薄膜修饰的红外表面等离子体共振传感器在波长测量模式下的特性研究

分别利用射频溅射法和溶胶-凝胶模板法,在玻璃基板上制备45nm厚的金膜和45 nm厚的SiO2介孔薄膜,用作表面等离子体共振(SPR)芯片,然后基于Kretschmann结构和共振波长测量模式构建了近红外SPR传感器.实验表明,在宽带平行光入射条件下,随着入射角度(θ)的减小,共振波长(λR)红移,折射率灵敏度(S=ΔλR/n)迅速提高.在θ=8°时测得的折射率灵敏度为24241 nm/RIU,是θ=15°所对应的灵敏度(2524.2 nm/RIU)的9.6倍.与常规的裸金SPR传感器相比,在相同的共振波长下,SiO2介孔薄膜修饰层使得SPR共振吸收峰明显变窄,光谱分辨率升高.低浓度溶菌酶水溶液在θ=10°时测得的SPR近红外共振波长随溶菌酶浓度增大而线性红移,其斜率为ΔλR/C=1.5×107nm· L/mol,即溶菌酶浓度增加6.67×10-8 mol/L能够导致共振波长红移1nm.1×10-7 mol/L Cu2+溶液可使SPR共振波长红移3nm.     

L-肉碱分子表面印迹聚合物的制备及其识别性能研究

以L-肉碱(L-carnitine)作为印迹模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用硅胶表面分子印迹技术合成了L-肉碱分子印迹聚合物(MIP)和非印迹聚合物(NMIP).通过紫外光谱研究了MAA与L-肉碱之间的结合作用.利用IR和SEM测试分别对产物进行了结构表征和表面形貌观察,说明分子印迹聚合物成功接枝到了硅胶表面.吸附动力学实验结果表明,MIP对L-肉碱有较好的识别性和吸附性;Scatchard分析表明该印迹聚合物中存在着一类等价的结合位点,最大表观结合量为71.00μmol/g,离解常数Kd=2.76×10-4mol/L;选择性吸附实验结果表明,MIP对L-肉碱的吸附结合量高于其D型异构体和其他类似物;拆分实验结果表明,MIP对DL-肉碱的拆分有一定作用.     

电聚合分子印迹传感器选择性测黑茶中槲皮素的含量

以槲皮素作为模板分子,邻氨基苯酚作为功能单体,在金电极表面通过电聚合法,制备了具有选择性识别槲皮素的分子印迹传感器。采用循环伏安法、差分脉冲伏安法研究了印迹膜的性能、结构和分子印迹效应。对功能单体与模板分子的配比、洗脱时间和印迹时间等实验参数进行了优化,并与其结构相似的化合物芦丁的选择性响应进行了比较,发现该传感器对槲皮素分子具有良好的选择性。槲皮素浓度在6.0×10-6~1.0×10-4mol/L范围内与峰电流呈线性关系,线性方程为:I(μA)=27.79+9.48lgc(mol/L)(R=0.9939),检出限为2.0×10-6mol/L。用此传感器测定黑茶中槲皮素含量的结果较为满意。     

基于制备接枝型分子印迹膜构建农药电位型电化学传感器及其检测性能研究

基于分子设计,以氯甲基化聚砜(CMPSF)为基膜,阴离子单体对苯乙烯磺酸钠(SSS)为功能单体,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,在表面引发体系-NH2/S2O2-8的作用下,采用"接枝聚合与分子印迹同步进行"的分子表面印迹新技术,制备了接枝型农药抗蚜威分子印迹膜(MIM)。采用红外光谱(FITR)和光学显微镜(OM)对该分子印迹膜进行表征,通过等温结合实验与竞争吸附实验,考察了抗蚜威分子印迹膜的分子识别性能与机理。以该印迹膜作为敏感膜,构建了抗蚜威电位型传感器,并对其检测性能进行了考察。结果表明,所制备的接枝型印迹膜对模板抗蚜威分子具有特异的识别选择性和优良的结合亲和性,结合容量高达92μg/cm2,相对于分子结构与抗蚜威相似的阿特拉津,印迹膜对抗蚜威的选择性系数为4.537。在p H 4.0的水介质中,传感器膜电极的电位响应与抗蚜威浓度对数在1.0×10-6~1.0×10-3mol/L范围内呈良好的线性关系(r=0.999 9),其检出限为2.5×10-8mol/L;以抗蚜威分子印迹膜为敏感膜所构建的电位型传感器,其构建过程简捷,检测灵敏准确,电位响应快速(t10 s)。     

分子印迹碳微球的制备及对偶氮染料选择性吸附和高灵敏度检测北大核心CSCD

以纤维素碳微球为内核,以活性艳红K-2BP染料为模板分子,采用蒸馏-沉淀法合成了K-2BP表面印迹碳微球(K-2BP-MIPs)。染料动力学吸附研究表明K-2BP-MIPs对模板分子K-2BP的最大吸附容量可达881 mg·g^(-1)。以Al_(x)Fe_(y)-MOF为导电糊剂,制备了K-2BP-MIPs和Al_(x)Fe_(y)-MOF共修饰的铁糊电极(FPE)用来构建分子印迹电化学传感器。采用循环伏安法(CV)和电化学阻抗法(EIS)研究了印迹电化学传感器的性能,结果表明该传感器在检测K-2BP时,孵育后和洗脱后的电流响应差值与K-2BP浓度在1.0×10^(-11)~5.0×10^(-7)mol·L^(-1)范围呈良好线性关系,检测限(S/N=3)是3.3×10^(-12)mol·L^(-1)。此外,传感器检测K-2BP时的电流响应差值分别是检测甲基红、活性黑五和亚甲基蓝的2.8、2.8和2.4倍,说明其具有良好的特异性。该印迹聚合物无论是在吸附还是检测方面,都具有优异的性能,在检测印染废水的排放方面有一定的应用价值。     

基于分子印迹聚合物的SPR传感器用于牛血清蛋白的检测

以牛血清蛋白（BSA）为模板分子、多巴胺为功能单体和交联剂、高碘酸钠为氧化剂，制备了BSA表面印迹表面等离子共振（SPR）生物传感器。通过聚丙烯酸（PAA）与BSA的氢键作用预先固定BSA，增加印迹效率，同时在聚多巴胺表面非印迹区域修饰部分水解的聚（2-甲基-2-噁唑啉）（PMOXA-EI）抵抗蛋白质的非特异性吸附。通过X射线光电子能谱、原子力显微镜、可变角光谱椭偏仪和静态水接触角对制备的BSA表面印迹SPR生物传感器进行表征。对质量浓度为0.1～10μg/mL的BSA水溶液进行SPR吸附研究，检测限和定量限分别达到了53 ng/mL和161 ng/mL。以β-乳球蛋白、卵白蛋白、溶菌酶和细胞色素C为参比蛋白进行选择性研究，相应的选择性系数分别达到了4.43、3.45、3.17和3.64。上述5种蛋白混合溶液中BSA的检测回收率为97.5%～102.5%。     

Detection of parathion methyl using a surface plasmon resonance sensor combined with molecularly imprinted films

An ultra-sensitive and highly selective parathion methyl(PM) detection method by surface plasmon resonance(SPR) combined with molecularly imprinted films(MIF) was developed. The PM-imprinted film was prepared by thermo initiated polymerization on the bare Au surface of an SPR sensor chip.Template PM molecules were quickly removed by an organic solution of acetonitrile/acetic acid(9:1,v/v), causing a shift of 0.58 in SPR angle. In the concentrations range of 10à13–10à10mol/L, the refractive index showed a gradual increase with higher concentrations of template PM and the changes of SPR angles were linear with the negative logarithm of PM concentrations. In the experiment, the minimum detectable concentration was 10à13mol/L. The selectivity of the thin PM-imprinted film against diuron,tetrachlorvinphose and fenitrothion was examined, but no observable binding was detected. The results in the experiment suggested that the MIF had the advantages of high sensitivity and selectivity.     

A 3,3′-dichlorobenzidine-imprinted polymer gel surface plasmon resonance sensor based on template-responsive shrinkage

Molecularly imprinted polymer gel film on the gold substrate of a chip was prepared with minute amount of cross-linker for the fabrication of a surface plasmon resonance (SPR) sensor sensitive to 3,3′-dichlorobenzidine. The molecularly imprinted gel film was anchored on a gold chip by a surface-bound photo-radical initiator. The sensing of 3,3′-dichlorobenzidine is based on responsive shrinkage of the imprinted polymer gel film that is triggered by target binding. This change can improve the responsiveness of the imprinted SPR sensor to 3,3′-dichlorobenzidine. The molecularly imprinted polymer gel film was characterized with contact angle measurements, electrochemical impedance spectroscopy, cyclic voltammogram, swelling measurements and atomic force microscopy. The changes of SPR spectroscopy wavenumber shifts revealed that the imprinted gel sensing film can ‘memorize’ the binding of 3,3′-dichlorobenzidine compared to non-imprinted one. The imprinted gel-SPR sensor showed a linear response in the range of 9.0 × 10⁻¹² to 5.0 × 10⁻¹⁰ mol L⁻¹ (R² = 0.9998) for the detection of 3,3′-dichlorobenzidine, and it also exhibited high selectivity to 3,3′-dichlorobenzidine compared to its structurally related analogues. We calculated the detection limits to be 0.471 ng L⁻¹ for tap water and 0.772 ng kg⁻¹ for soil based on a signal to noise ratio of 3. The method showed good recoveries and precision for the samples spiked with 3,3′-dichlorobenzidine. This suggest that the imprinted gel-SPR sensing method can be used as a promising alternative for the detection of 3,3′-dichlorobenzidine.     

A novel method to prepare SPR sensor chips based on photografting molecularly imprinted polymer

A novel method to prepare surface plasmon resonance(SPR) sensor chips based on grafted imprinted polymer is explored. Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP) films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules.     

A novel polymerization of ultrathin sensitive imprinted film on surface plasmon resonance sensor

A new surface-initiated polymerization based on pasting the initiator on a sensor chip surface was applied to prepare a malachite green (MG) imprinted ultrathin film on a surface plasmon resonance (SPR) sensor. First, the initiator (2,2-azoisobutyronitrile) was pasted on the gold surface using polyvinyl chloride (PVC). The initiator-covered gold chip was then soaked in a pre-polymerization solution prepared by dissolving methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker), and MG (template) in DMSO in a weighing bottle. Finally, the weighing bottle was placed in a vacuum oven and thermal-initiated polymerization was conducted at 60 °C for 16 h. This method was simple and time-saving compared with the commonly used surface-initiated polymerization. More importantly, the molecularly imprinted polymer (MIP) film prepared using this method was much thicker than that of commonly used methods; the adsorption quantity was also much larger. The MIP modified SPR sensor showed high sensitivity and selectivity as well as good stability in detecting MG. The results suggest that the ultrathin MIP film prepared using the new method in this study is suitable to serve as the recognition element of the SPR sensor.     

Molecularly Imprinted Polymer Thin Film Based Surface Plasmon Resonance Sensor to Detect Hemoglobin

Molecularly imprinted polymer（MIP） films for hemoglobin detection were prepared onto the Au/Cr coated surface plasmon resonance（SPR） sensor chips by the in situ electropolymerization of 3-aminophenylboronic acid（3-APBA）.The formation of the films and rebinding processes of hemoglobin were monitored by in situ electrochemical-SPR（EC-SPR） spectroscopy,with allowed real-time observation of the simultaneous changes in electrochemical and optical properties of the films.Scanning electron microscopy（SEM） and atomic force microscopy（AFM）were used to characterize the surface morphologies of the MIP films.The effects of pH,ion strength,different metal ions on rebinding Hb,the specific binding and the selective recognition were investigated.The results obtained with the molecular imprinted SPR chips indicate a good adsorption of Hb in a range of 0.0005-5 mg/mL in 0.05 mol/L sodium phosphate buffer at pH=7.0.A linear calibration curve（R2=0.94） of the SPR sensor for Hb detection was obtained in a range of 0.05-5 mg/mL.The detection limit for hemoglobin by this method was 0.000435 mg/mL（S/N=3）.Interference studies indicate that the MIP films have a good selectivity compared with the referenced proteins.The stability of the sensor was also established.Results indicate that the SPR sensor chip keeps 87.6％ of its original response after 14 d of storage under dry and ambient conditions.     

Continuous Immunoassay for Sulfamethazine by Surface Plasmon Resonance-Based Biosensor

Regeneration of the sensor chip surface is difficult in many surface plasmon resonance (SPR) biosensor assays. Improper regeneration will reduce life span of the sensor chip and decrease the quality of the data. Considering the advantages of reducing the regeneration frequency, a theoretically feasible continuous SPR biosensor immunoassay for sulfamethazine (SMT) was developed. In the continuous inhibitive immunoassay, the sensor chip surface is regenerated only once after a definite number of tests instead of every test. The SMT-bovine serum albumin (BSA) conjugate was covalently immobilized to a carboxymethyldextran modified gold film. The immobilization conditions of the antigen were studied and the working dilution of the antibody was optimized. The antibody was mixed with SMT of different concentrations prepared with PBS buffer to construct the calibration curve. The limit of detection was 0.5 ng mL^?1. The continuous SPR biosensor assay was proved to be simpler and more practical than a normal one.     

Flow immunoassay of trinitrophenol based on a surface plasmon resonance sensor using a one-pot immunoreaction with a high molecular weight conjugate

A surface plasmon resonance (SPR) immunosensor based on a competitive immunoreaction for the determination of trinitrophenol (TNP) is described. A goat anti-mouse IgG (1st antibody), which recognizes an Fc moiety of an antibody, was immobilized on a gold film of an SPR sensor chip by physical adsorption. A TNP solution containing a fixed concentration of a mouse anti-TNP monoclonal antibody (2nd antibody) and a TNP-keyhole limpet hemocyanin (KLH) conjugate was incubated in one-pot and introduced into the sensor chip. The TNP-KLH conjugate competes with TNP for binding with the 2nd antibody. The resulting complex of the 2nd antibody with the TNP-KLH conjugate was bound to the 1st antibody, which is immobilized on the sensor chip. The SPR sensor signal based on resonance angle shift is dependent on the concentration of TNP in the incubation solution in the range from 25 ppt to 25 ppb, and the coefficient of variation of the SPR signals for the 25 ppb TNP solution was determined to be 13% (n = 4). The experimental results for the adsorption constant of the 1st antibody on the sensor chip and the binding constant of the 1st antibody complex with the 2nd antibody are discussed, together with theoretical considerations.     

Molecularly Imprinted Polymer Film Grafted from Porous Silica for Selective Recognition of Testosterone

Abstract

A type of testosterone‐imprinted polymer film grafted from porous silica was prepared by covalently binding azo‐initiators and then photo‐grafting. Elemental analysis and infrared (IR) spectroscopy attested the polymer formation. The material could be polymerized within 10–60 min with reproducible grafting kinetics, controllable film thickness, and obviously specific recognition ability to testosterone with the imprinting factor of 1.52. Due to its uniform size, spherical shape, controllable film thickness, and accessible sites near or at the surface, this polymer could serve as a sensing element, solid‐phase extraction material, or chromatographic stationary phase to selectively recognize or separate testosterone.     

基于金银合金薄膜的波长检测型表面等离子体共振传感器

从实验和理论两方面详细研究了金银合金膜表面等离子体共振(SPR)传感器在可见光波段的敏感特性.实验方面,通过在玻璃基底上溅射50 nm厚的金银合金薄膜制备了一种新型的SPR传感芯片,并且自行搭建了基于Kretschmann结构的波长检测型SPR传感器测试平台.利用不同浓度的氯化钠(NaCl)水溶液和浓度为10μmol·L-1的牛血清蛋白(BSA)水溶液分别作为折射率样品和分子吸附样品,研究了传感器的折射率灵敏度和吸附灵敏度,并与金膜和银膜SPR传感器进行了对比研究.结果表明,对于折射率灵敏度的测试,金银合金膜SPR传感器大幅高于金膜SPR传感器,略低于银膜SPR传感器;而对于吸附敏感的研究,金银合金膜SPR传感器的灵敏度与银膜SPR传感器相近,是金膜SPR传感器的3倍.理论方面,利用菲涅尔公式和等效折射率计算公式仿真计算了这三种薄膜结构的SPR传感器的灵敏度和精确度,结果指出金银合金膜SPR传感器的灵敏度与银膜SPR传感器接近,是常规金膜SPR传感器的2.31倍,而半高峰宽仅为金膜和银膜SPR传感器的1.36倍.在稳定性方面,金银合金膜SPR传感器与金膜SPR传感器均具有良好的化学稳定性,而银膜SPR传感器较易氧化,使用寿命低,不常被采用.综上,金银合金膜在改善传感器灵敏度的同时,不会降低精度,是一种高灵敏、低成本、良好稳定性的SPR传感器敏感材料.