适用于鱼肉中氯霉素检测的抗体包被金磁纳米微粒修饰安培免疫传感器研究

研制了基于氯霉素抗体包被Fe3O4/Au金磁纳米微粒(GMP)和三乙撑四胺铜(II)(CuL)共固定修饰平面热解石墨电极的安培免疫传感器(PRG|CuL / anti CAP-GMP),用于测定鱼肉中CAP含量.该免疫传感器是利用外加磁场,将anti CAP-GMP吸引到CuL修饰的PRG电极(PRG|CuL)表面制备而成.CuL对H2O2还原具有良好的电催化能力,当该传感器在含CAP样品液中温育后,CAP与电极表面的anti CAP的免疫结合物导致CuL对H2O2的催化还原电流(I)降低,电流下降值(△I)和CAP浓度成正比,可用于CAP定量测定.在25℃的pH=6.5磷酸盐缓冲液(PBS)中温育30 min,该传感器对CAP的检测线性范围为0.6~110 ng/mL,检出下限为0.092 ng/mL(3σ法).应用于鱼肉中CAP检测并与传统的液相色谱法(HPLC)比较,结果一致,其添加回收率在97%~104%之间.该免疫传感器集分离、富集为一体,电极表面可更新,检测灵敏快速,对于水产品中痕量氯霉素分析提供了一种新颖的方法.     

基于铜配合物和抗体包被化学镀纳米金共固定的癌胚抗原安培免疫传感器

研制了基于抗体包被化学镀纳米金(AuNPs)和[Cu (bpy) 2 (ONO)]NO3配合物(CuL）共固定修饰玻碳电极(GCE)的安培免疫传感器,并用于血清中癌胚抗原(CEA)的检测。首先将GCE电极表面氧化形成羧基,进而键合上乙二胺。将此胺化电极浸泡在CuL和化学镀金溶液后, CuL可通过π-π堆积作用吸附到GCE表面,并在电极表面还原成30~50 nm的纳米金层（GCE|CuL/AuNPs）。将上述电极浸泡在CEA抗体(anti CEA)溶液中,利用AuNPs固定anti CEA,并通过辣根过氧化物酶(HRP)封闭剩余的AuNPs位点,由此构建了一类快速检测 CEA的无试剂安培免疫传感器（GCE|CuL-AuNPs /anti CEA-HRP）。由于HRP可以催化CuL和过氧化脲（CP）的氧化还原反应,因此该电极在CP溶液中形成催化还原电流。当该传感器在37 ℃下,含CEA的pH 6.5PBS溶液中温育30 min后,随着温育液中CEA浓度的增加,电极表面形成的免疫复合物也增加,导致CuL 对CP 的催化电流下降。电流下降百分比I%与CEA浓度在0.1~80 ng/mL 成线性关系,检测限为0.052 ng/mL（3σ）。由于采用化学镀法可以方便地在GCE表面制备纳米金膜进而包被抗体,并通过π-π堆积作用吸附CuL作为电子媒介体,故该免疫电极制备简单;采用可催化CP还原的HRP封闭AuNPs层多余位点,大大提高了电极灵敏度,有望用血清中痕量CEA分析。     

基于抗体包被纳米金和铜配合物共固定修饰电极的癌胚抗原安培免疫传感器研究

研制了基于抗体包被化学镀纳米金(AuNPs)和[Cu(bpy)2(ONO)]NO3配合物(CuL)共固定修饰玻碳电极(GCE)的安培免疫传感器,并用于血清中癌胚抗原(CEA)的检测。首先将GCE电极表面氧化形成羧基,进而键合上乙二胺。将此胺化电极浸泡在CuL和化学镀金溶液后,CuL可通过π-π堆积作用吸附到GCE表面,并在电极表面还原成30~50nm的纳米金层(GCE|CuL/AuNPs)。将上述电极浸泡在CEA抗体(anti CEA)溶液中,利用AuNPs固定anti CEA,并通过辣根过氧化物酶(HRP)封闭剩余的AuNPs位点,由此构建了一类快速检测CEA的无试剂安培免疫传感器(GCE|CuL-AuNPs/anti CEA-HRP)。其中CuL作为电子媒介体对过氧化脲(CP)有催化还原作用,而且HRP可增强这种作用。当该传感器在37℃下,含CEA的pH6.5PBS溶液中温育30min后,随着温育液中CEA浓度的增加,电极表面形成的免疫复合物也增加,导致CuL对CP的催化电流下降。电流下降百分比1%与CEA浓度在0.1~80ng/mL之间成线性关系,检测限为0.052ng/mL(3σ)。由于采用化学镀法可...     

一种检测莱克多巴胺的复合碳纳米材料修饰电化学传感器

将双壁碳纳米管(DWCNT)和氧化石墨烯(GO)超声分散在Nafion的乙醇溶液中,滴涂于玻碳电极(GCE)表面制得氧化石墨烯/双壁碳纳米管-Nafion复合材料修饰电极(GO/DWCNT-Nafion/GCE),可用于莱克多巴胺的灵敏检测。通过扫描电镜(SEM)对修饰电极表面形貌进行表征。使用差分脉冲伏安法(DPV)对莱克多巴胺在修饰电极上的电化学行为进行研究。实验结果表明,该修饰电极对莱克多巴胺表现出了强的电催化氧化效应。在pH=7.0的PBS缓冲体系中于-0.3 V下富集120 s后,该修饰电极对莱克多巴胺浓度在1.0×10-8~1.0×10-6mol/L范围内有着良好的线性响应,检测限为5.4×10-9 mol/L。同时,该电极选择性良好,表明该方法在食品安全检测领域具有实际应用前景。     

基于DNA-Hb修饰的聚合二氧化锆/金电极过氧化氢生物传感器的研究

以聚合二氧化锆(ZrO2)薄膜修饰的金电极为基底,通过在二氧化锆修饰电极表面滴涂DNA和血红蛋白(Hb)溶液制备了性能优良的DNA-Hb/ZrO2/Au过氧化氢传感器.该传感器对H2O2的还原显示出较好的电催化响应,固定在电极表面的Hb在0.1 mol/L(pH5.0)PBS中对过氧化氢响应灵敏度高,检测范围宽(1.7×10-7～3.0×10-3～mol/L),检测下限低(8.0×10-8～tool/L),并且表现出良好的热稳定性和高选择性.     

基于Au—Ni复合材料的新型葡萄糖传感器的研究

利用新型Au—Ni复合材料,通过壳聚糖将Au—Ni复合材料修饰到电极表面．制备了一种新型的用于葡萄糖检测的电化学传感器。以XRD表征了Au—Ni材料,以循环伏安法,交流阻抗法,计时电流等电化学方法研究了此传感器的电化学特性。研制的电极对葡萄糖检测的线性范围为2．5×10^-9．5×10^-4mol／L,检测限为lxl0...     

纳米Au修饰电化学传感器直接检测液相中沙林的研究

采用电势阶跃法,在Au电极表面修饰纳米Au,制备出的电化学传感器采用循环伏安法直接检测液相中的沙林,探讨了检测沙林的电化学反应机理.研究发现,检测沙林中,在1.4～0.1 V范围循环伏安扫描之前,预先进行2.0～-2.0V循环伏安扫描,是实现电化学方法检测沙林的重要先决条件.实验表明,纳米Au修饰Au电极表面后,提高了...     

一种基于纳米金／石墨烯／普鲁士蓝（PB）修饰玻碳电极非标记免疫传感器

采用电聚合的方法将普鲁士蓝（PBl聚合在玻碳电极表面,再将石墨烯修饰在PB上面,然后再采用电沉积的方法将HAuCL直接还原成纳米金粒子,沉积在石墨烯表面,最后将羊抗人IgG抗体直接固定于该修饰的玻碳电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器。利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法对人IgG抗原进行了测定。实验表明,此免疫传感器在含不同浓度人IgG的PBS溶液（pH6．98）中测定,响应电流与人IgG浓度在5．55～455．5ng／mL范围内有良好的线性关系,其相关系数r=0．9926,检测限为0．015ng／mL（S／N=3）。该免疫传感器具有制备简单、响应时间快（5min）、稳定性好等特点。     

基于纳米磁珠修饰印刷电极的牛奶中三聚氰胺检测安培免疫传感器

共固定氯代邻菲哕啉双核铜配合物(Cu2(phen)2Cl2(μ-Cl)2,简称CuzL)和包被三聚氰胺抗体(anti MA)的FbO4/Au胶(简称纳米磁珠)于丝网印刷电极(SPCE)表面,构建了一种测定牛奶中三聚氰胺(简称MA)含量的安培免疫传感器.当该传感器在含MA溶液中温育时,MA和同时加入的HRP标MA二抗(HRP-anti MA Ⅱ),与电极表面的anti MA形成三元免疫复合物.该复合物上的HRP能催化HzO2还原,并经过Cu2L传导在电极表面形成电流,电流强Ⅰ与MA浓度在0.5～40和60～100ng/mL范围内呈线性关系,检测限为0.25 ng/mL.在pH 6.2的PBS底液中,该传感器制作简单、可抛弃,对MA检测时间小于20 min,灵敏度为1μA·ng-1mL,明显高于酶联免疫吸附(ELISA)法;可实现牛奶中MA免分离现场分析.     

基于NaOH刻蚀玻碳电极的电化学传感器在检测膀胱癌DNA中的应用

制备了一种基于活化的玻碳电极的新型电化学DNA生物传感器,可用于膀胱癌DNA的检测.通过循环伏安法(CV)实现玻碳电极在NaOH溶液中的刻蚀,使电极表面负载大量官能团,为DNA提供连接位点,由Laviron方程计算得到玻碳电极表面的羧基浓度为 1.022×10-6 mol/cm2.亚甲基蓝(MB)作为电化学检测的杂交指示剂.采用原子力显微镜(AFM)对刻蚀后的电极进行了形貌表征.在最优杂交条件下,通过差分脉冲法(DPV)计算出最佳检测限为5.677×10-13 mol/L(n=5),适用目标 DNA浓度范围1×10-8 mol/L~1×10-12 mol/L.该传感器有望用于实际样品中膀胱癌DNA的快速检测.     

Quartz crystal microbalance and electrochemical cytosensing on a chitosan/multiwalled carbon nanotubes/Au electrode

The piezoelectric quartz crystal microbalance (QCM) was used to monitor the adhesion of mammalian cells on a chitosan (CS)/multiwalled carbon nanotubes (MWCNTs) composite modified gold electrode. The morphology and chemical properties of the CS/MWCNTs film were characterized with scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The human breast cancer cells (MCF-7) were adhered to and grown on the CS/MWCNTs film modified gold surface or a net CS film modified gold surface, and the process of which was continuously monitored and displayed by changes of the resonant frequency (Δf₀) and the motional resistance (ΔR₁) of the QCM. The attachment/spreading process of the MCF-7 cells on the QCM Au electrode decreased the Δf₀ and increased the ΔR₁ simultaneously, implying rather complicated effects (simultaneous mass, viscoelasticity and probable surface-stress load) on the sensor surface. The attachment rate and viability of the cells when proliferating on the two surfaces were detected by the MTT assay. The presence and state of cells on the electrode surface were confirmed by the fluorescent microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy of the ferricyanide/ferrocyanide couple were examined before and after the cell adhesion. All data showed that the cell adhesion and proliferation processes were more efficient on the biocompatiable nanocomposite surfaces. The cell-based biosensor has potential for identification and screening of biologically active drugs and other biomolecules affecting cellular shape and attachment.     

可再生使用的磁性纳米修饰C反应蛋白电流型免疫传感器

利用Fe3O4(核)/Au(壳)(简称GMPs)标记C反应蛋白酶标抗体(HRP-anti CRP),构建了一类新型的磁性纳米探针(HRP-anti CRP/GMPs),将其修饰在丝网印刷电极(SPCE)表面构建了可再生使用的CRP安培型酶联免疫传感器.首先将多壁碳纳米管(MCNTs) -硫堇(Thi) -Nafion复...     

自组装CA125免疫传感器的研制及其对血清中CA125的分析

利用自组装的方法在金电极上制得巯基丁二胺钌(Ⅲ)/纳米金胶/卵巢癌抗体(抗CA125)免疫修饰电极.用该修饰电极对CA125进行检测,发现溶液中CA125 抗原分子和传感器表面固定化CA125抗体发生免疫反应.结果显示: CA125 抗体导致了该传感器电流的降低.在优化的实验条件下,样品中CA125浓度在2～140 unit/mL 范围内与电流降低成线性关系,检测限为0.8 unit/mL.该免疫传感器表现出良好的准确性和精确性.对40 unit/ mL的CA125重复测定8次,相对标准偏差约为2.9%.该传感器具有较好的制备重复性和稳定性.该方法的提出为卵巢癌临床免疫分析提供了一种有前景的方法.     

多壁碳纳米管-Nafion/纳米金构建阻抗传感器研究

利用多壁碳纳米管（ MWNT）—Nafion和纳米金（ GNPs）修饰金电极构建了一种简单、灵敏检测人端粒DNA的电化学阻抗传感器。首先将Nafion分散的MWNT滴涂于Au电极表面,再利用电化学沉积法将GNPs沉积到MWNT—Nafion修饰Au电极表面,以GNPs为载体固定人端粒探针DNA制备DNA传感器。在最优实验条件下,将传感器用于人端粒DNA的检测中,结果表明：目标人端粒DNA的线性范围为1.0×10－13～5.0×10－11mol/L,检出限（S/N＝3）为2.5×10－14mol/L。采用MWNT为基底沉积GNPs修饰电极检测的灵敏度显著提高。     

基于Au NPs-CeO2@PANI纳米复合材料固定化酶的葡萄糖生物传感器

制备了一种基于金纳米粒子(Au NPs)、氧化铈纳米颗粒(CeO2)和导电聚苯胺(PANI)的具有核壳结构的纳米复合材料(Au NPs-CeO2@PANI),利用该纳米复合材料和壳聚糖形成的复合膜成功实现了对葡萄糖氧化酶(GOD)的固定.采用透射电镜和X射线衍射对Au NPs-CeO2@PANI材料进行了表征.电化学方法研究了传感器性能,结果表明基于Au NPs-CeO2@PANI纳米复合材料修饰的葡萄糖生物传感器线性范围为6.2×10-6 mol/L～2.8×10-3 mol/L,响应时间为5 s,检测下限为1.0×10-6 mol/L;相同条件下Au NPs-CeO2@PANI纳米复合材料修饰的电极也显示出了比单一或二者复合的纳米材料修饰电极更优越的性能.     

MWNTs与GNPs—CHIT修饰的过氧化氢生物传感器

在玻碳电极（GCE）上自组装一层多壁碳纳米管（MWNTs）,构建负电荷的界面,然后,静电吸附一层阳离子电子媒介体硫堇（Thi）,再由共价键作用自组装一层纳米金（GNPs）,壳聚糖（CHIT）混合溶液的复合薄膜,通过静电吸附辣根过氧化物酶（HRP）制得过氧化氢（H2O2）生物传感器。采用循环伏安法和计时电流法考察了该生物传感器的电化学性质,并研究了该修饰电极对H2O2的催化还原作用。生物传感器的响应电流与H2O2浓度在8．2×10^-6～1．1×10^-3mol／L范围内呈现线性关系,检出限为5．8×10^-7mol／L,达到95％稳态响应时间约为15s。将此生物传感器用于H2O2的检测,结果令人满意。     

Fabrication of a novel electrochemiluminescence glucose biosensor using Au nanoparticles decorated multiwalled carbon nanotubes

Au nanoparticles (nanoAu) with an average diameter of 60 nm were decorated on the surface of multiwalled carbon nanotubes to prepare MWCNTs-nanoAu nano-hybrids. The MWCNTs-nanoAu nano-hybrids were cast on the surface of a glassy carbon electrode and were then further modified with a layer comprising glucose oxidase and chitosan to fabricate a novel electrochemiluminescence (ECL) glucose biosensor. The biosensor showed a remarkably improved electrocatalytic activity towards luminol oxidation and significant improvement in its ECL response. The proposed ECL biosensor exhibited excellent performance for glucose detection with a wide linear range (1-1000 μM), low detection limit (0.5 μM), excellent reproducibility (0.5%) and satisfactory selectivity.     

Replica exchange molecular dynamics simulation of chitosan for drug delivery system based on carbon nanotube

Chitosan is an important biopolymer in the medical applications because of its excellent biocompatibility. It has been recently highlighted in the targeted drug delivery system (DDS) by improvement of the carbon nanotube (CNT) solubility. To investigate the effect of chitosan length, the two targeted DDSs with 30 and 60 chitosan monomers were performed by replica-exchange molecular dynamics simulations at temperatures in the range of 300–455 K with three different combinations of force fields and implicit solvation models. Each DDS model contains the epidermal growth factor (EGF), chitosan (CS) of 30 (30CS) and 60 (60CS) monomers, single-wall CNT (SWCNT) and gemcitabine (Gemzar) as the model payload anticancer drug, called EGF/30CS/SWCNT/Gemzar and EGF/60CS/SWCNT/Gemzar, respectively. The SWCNT confines gemcitabine inside its cavity, while the outer surface is wrapped by chitosan in which one end is linked to the EGF. Even though the REMD results from different force fields and implicit solvation models are not exactly identical, all of them are in the same trend confirming that in the EGF/30CS/SWCNT/Gemzar DDS the 30CS chain was not long enough to wrap around the SWCNT, and consequently the EGF was located so close to the tube as to potentially cause steric inhibition of the binding of EGF to its receptor (EGFR), which is highly expressed on the surface of cancer cells. On the other hand, this phenomenon is not observed in the EGF/60CS/SWCNT/Gemzar DDS in which the 60CS was found to completely wrap over the CNT outer surface using only 50 chitosan units. The evidence suggested that a ratio of chitosan molecular weight per SWCNT surface area larger than 9.9 × 10⁻⁷ kg/m² is suitable for application in targeted DDSs. Although an increase in the temperature is likely to influence the overall DDS structure, and especially the orbit of helical chitosan on the SWCNT and the EGF conformation, gemcitabine is still encapsulated inside the tube.     

基于静电沉积壳聚糖铂纳米颗粒复合膜构建葡萄糖生物传感器

利用电沉积方法对壳聚糖/铂纳米颗粒复合膜进行组装,以戊二醛作为交联剂同定葡萄糖氧化酶,构建葡萄糖生物传感器.实验结果表明:制得的葡萄糖生物传感器响应时间仅为8 s,线性测量范围为1×10-5～1×10-3moL/L,检测限为1.4×10-5 mol/L(S/N=3.0).该传感器灵敏度高,稳定性好.     

Electrochemical copper (II) sensor based on self-assembled 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate

A 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate (AHMP)-based self-assembled monolayer (SAM) was formed on the gold electrode surface. Ellipsometric measurements evidenced the SAM formation on the gold electrode surface. The structural integrity of the modified gold electrode was also characterized by insulating properties of the SAM that were detected by cyclic voltammetry. The results of cyclic voltammetry showed that the SAM, which was formed by assembly of AHMP, was stable but did not completely block the redox-activity of ferrocene and K₃[Fe(CN)₆]/K₄[Fe(CN)₆]. In contrast completely blocked redox-activity was observed after the treatment of AHMP-based SAM with saturated solution of 4-formylphenylboronic acid in 1,4-dioxan. The modified electrodes exhibited a selective response towards Cu(II) ions in the presence of some interfering ions such as Cd(II), Co(II), Fe(II), Ni(II) and Pb(II). This study is the first scientific report on the application of AHMP-modified electrode as a selective Cu(II) sensor in the presence of some interfering cations.