基于氧化还原体系纸芯片法对血清尿酸含量的快速检测

建立了以纸芯片为分析平台的尿酸含量快速检测方法.基于尿酸的还原性,以FeCl3为氧化剂组成氧化还原体系,以邻二氮菲为显色剂对反应产物Fe2+进行显色,根据显色强度对尿酸含量进行测定.结果 表明,当FeCl3与尿酸比例为1.6∶1,反应10 min,显色剂pH 7.4时显色最佳.显色强度(RGB值)与尿酸浓度在1.19～...     

纸芯片制作及其在化学发光法检测葡萄糖和尿酸中的应用

纸芯片是一类新型的个性化诊断器件,可快速、廉价、简便地进行多组分分析.采用光刻法制备了一维和二维纸芯片(μPADs),并对不同通道芯片检测所需的样品体积进行理论估算.同时利用葡萄糖氧化酶-葡萄糖反应产生过氧化氢诱导鲁米诺化学发光,在纸芯片上检测葡萄糖,线性范围为2.0×10-4～9.0×10-4mol/L,检出限为5....     

基于氢键作用的金纳米粒子比色法检测尿酸

尿酸含量高可使人产生痛风等疾病,尿酸的测定是临床检测重要的生化指标之一。金纳米粒子比色法检测尿酸实验联系实际生活,将科研前沿和教学内容有机结合起来,可以激发学生的学习兴趣,加深学生对经典理论的理解,增加学生对科研前沿的了解。本实验利用金纳米粒子吸光系数高的特点,通过尿酸与三聚氰胺反应后,抑制三聚氰胺诱导的金纳米粒子聚集,从而达到检测尿酸的目的。随着溶液中尿酸浓度的增加,溶液颜色由蓝变红,差别明显,视觉效果好,容易分辨。     

基于微流控纸芯片-显色法快速测定全血中尿酸的含量

提出了基于微流控纸芯片-显色法快速测定全血中尿酸含量的方法。使用喷蜡打印机将设计的微通道网格打印在色谱纸上,经过加热处理得到微流控纸芯片。在微流控纸芯片I区(样品预处理区)滴加3.2μL 0.10 g·mL^-1乙二胺四乙酸(EDTA)溶液和4.8μL 0.015 g·mL^-1壳聚糖溶液,干燥,得到微流控纸芯片检测平台。全血样品与磷酸盐缓冲液(pH 7.4)按体积比1∶4混合,分取混合溶液13μL滴加至I区,红细胞与血浆在壳聚糖和EDTA的凝集作用下发生分离,血浆流动至II区(显色区);待血浆完全铺满II区后,滴加3μL三氯化铁和邻二氮菲的混合溶液,静置反应2 min,用手机拍照,采用Photoshop CS2软件分析显色区的颜色强度,得到RGB值(红、绿、蓝三色叠加值),根据标准曲线计算尿酸含量。结果表明：全血中葡萄糖等常见还原性物质均不影响尿酸含量的测定;尿酸浓度在0.05～0.85 mmol·L^-1内与RGB值呈线性关系,检出限(3.3s/k)为0.03 mmol·L^-1。方法用于实际全血样品分...     

抗体与多酶负载纳米金的合成表征及纸上化学发光性能研究——介绍一个仪器分析综合实验

对抗体及多酶负载纳米金的合成、表征及纸上化学发光性能进行了研究,实验结合了目前的研究成果,内容涵盖了材料化学、仪器分析、无机合成、胶体化学等方面,涉及材料和生物分析等领域。本实验还可进行后续癌症标志物免疫分析的拓展实验研究,可作为8学时的仪器分析综合实验,给大学三年级的学生开设。     

检测痕量纳米金的纳米催化光度法

在EDTA—NaOH介质中,金纳米微粒对盐酸联氨还原硫酸铜生成铜微粒这一慢反应具有较强的催化作用．铜微粒在750nm处产生一个吸收峰．随着纳米金浓度的增大,750nm处的吸光强度线性增大．对于粒径为10、30、50nm的纳米金,其线性范围、回归方程、检出限分别为0．12～1．68、0．36～2．80、1．00～5．00nmol／L,△A750nm=0．3205CAu＋0．0076、△A750nm=0．2201CAu＋0．0056、△A750nm=0．1150CAu＋0．0066,0．05、0．20、0．50nmol／L Au．分别对0．50、1．00nmol／L纳米金（d=10nm）平行测定10次,求得其相对标准偏差分别为4．2％、3．5％．     

金纳米球和金纳米棒的制备及其光热催化性能

以氯金酸(HAuCl_4)为原料,硼氢化钠(NaBH_4)为还原剂,聚乙烯吡咯烷酮K30(PVP)为稳定剂制备了尺寸5 nm的金纳米球;以阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)为模板剂和油酸钠(NaOL)稳定剂,用种子生长法制备了不同长径比(R=2.5~4)的金纳米棒。在2 W·cm~(-2)的808 nm激光照射10 min条件下,C(0.4 mg·mL~(-1))浓度金纳米球溶液升温10.2℃,该溶液可催化血液中亚硝基硫醇释放NO,最大释放量可达1.42 nmol·L~(-1);相同光热及催化条件下,C(0.4 mg·mL~(-1))浓度金纳米棒(R=3.01)溶液升温41.3℃,该溶液催化血液中亚硝基硫醇释放NO最大释放量可达1.89 nmol·L~(-1)。金纳米球和金纳米棒的光热及催化性能随着浓度增加而增强,金纳米棒的光热及催化性能要优于金纳米球。     

金纳米粒子-石墨烯修饰玻碳电极的制备及对多巴胺、抗坏血酸和尿酸的同时检测

采用三步法制备了金纳米粒子-石墨烯层层组装的复合材料,并将其修饰在玻碳电极上,制备成一种新型的同时检测抗坏血酸(AA)、多巴胺(DA)和尿酸(UA)的电化学传感器。采用扫描电子显微镜(SEM)对复合材料进行了表征,并研究了传感器对AA、DA、UA电催化性能。结果表明:该传感器对AA、DA和UA的氧化具有很好的催化和分离效果,可实现AA、DA和UA的同时测定。在三者共存体系中,AA-DA、DA-UA、AA-UA的氧化峰电位差分别为152mV、161mV和313mV。线性范围分别为1.996×10-5~5.580×10-3、1.996×10-6~5.478×10-3和1.000×10-6~1.000×10-3 mol/L,检出限分别为1.200×10-5、1.030×10-7和4.100×10-7 mol/L。该修饰电极选择性好、稳定性高,有望用于实际样品中AA、DA和UA的同时检测。     

各向异性金纳米粒子的制备及其在催化中的应用

尽管有关金纳米粒子催化的研究工作很多,但其中大多数都是采用传统的浸渍法将金盐负载到载体上、共沉淀或沉积-沉淀法制得负载的纳米粒子,但这些方法并未吸收最新的纳米技术。最近,金催化剂的研究者开发了在胶态悬浮液中制取金属纳米粒子,然后进行固载,从而使得单金属和双金属催化剂的催化活性和形貌控制取得较大进展。另一方面,最近十年出现了金纳米粒子合成的高级控制技术,得到了许多各向异性的金纳米粒子,且很容易制得新的形貌,可以控制纳米粒子的表面原子配位数和光学特性(可调的等离子体带),这些都与催化密切相关。这些形貌包括纳米棒、纳米星、纳米花、树枝状纳米结构或多面体纳米粒子等。除了高度关注各向异性金纳米粒子的最新开发的制备方法和性质,本综述也清楚地总结了这些纳米粒子独特的催化性能,以及通过提供更高催化性能的金催化剂、控制暴露的活性位,以及热、电和光催化的鲁棒性和可调性,从而给多相催化领域带来令人惊奇的潜在变革。     

纸芯片微流控技术的发展及应用

纸芯片微流控技术是一种新型微流控技术。相比于以玻璃、石英、高聚物等为基底的传统微流控芯片,纸芯片具有成本低、易操作、可携带、耗样量小等优点。该文介绍了纸芯片的发展及常用的制作方法,并举例说明了光度法、荧光法、化学发光及电化学发光法和电化学法在纸芯片检测中的应用;归纳了纸芯片技术在临床诊断、环境监控以及食品安全分析等方面的应用;最后对纸芯片微流控的应用前景进行了展望。     

The Influence of Gold Nanoparticles on Simultaneous Determination of Uric Acid and Ascorbic Acid

A three-dimensional L-cysteine (L-cys) monolayer assembled on gold nanoparticles (GNP) providing simultaneous detection of uric acid (UA) and ascorbic acid (AA) was studied in this work. The cyclic voltammetry demonstrated that, at a bare glassy carbon electrode (GCE) or planar gold electrode, the mixture of UA and AA showed one overlapped oxidation peak; whereas when the electrode was modified with GNP, the oxidation peaks for UA and AA were separated. While a GNP modified electrode was further modified with L-cys monolayer (L-cys/GNP/GCE), namely, three-dimensional L-cys monolayer, a better separation for UA and AA response was obtained. Interestingly, the L-cys monolayer-modified planar gold electrode presented a block effect on the oxidation of AA, which was facilitated by the three-dimensional L-cys monolayer attributed to its distinct structure. The pH of solution presented a noticeable effect on the separation of UA and AA at GNP modified electrodes with or without L-cys monolayer. Wide concentration ranges from 2 × 10^?6?1 × 10^?3 M to UA and 2 × 10^?6?8 × 10^?4 M to AA could be obtained at L-cys/GNP/GCE.     

Simultaneous Determination of Ascorbic Acid,Dopamine and Uric Acid Based on Gold Nanoparticles‐PTCA‐Cys Composites Modified Electrodes

In this study, a nanocomposite of 3, 4, 9, 10‐perylenetetracarboxylic acid and L‐cysteine (PTCA‐Cys) with satisfactory water‐solubility and film‐forming ability was prepared and worked as substrate for modifying the glassy carbon electrode. Then, gold nanoparticles (AuNPs) were immobilized to achieve a PTCA‐Cys‐AuNPs modified electrode which provided more reaction positions on the sensor. Scanning electron microscopy, transmission electron microscopy, cyclic voltammetry and different pulse voltammetry were employed to characterize the assembly process of the sensor. The constructed sensor displayed desirable sensitivity, selectivity and stability towards the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Under the optimal experimental conditions, the oxidation peaks of AA, DA and UA appeared at 64, 240 and 376 mV, respectively. The corresponding linear response ranges were 3.2–435, 0.04–100 and 0.80–297 μM, and the detection limits were 1.1, 0.010 and 0.27 μM (S/N=3), respectively.     

Electrochemical Determination of Tyrosine in the Presence of Dopamine and Uric Acid at the Surface of Gold Nanoparticles Modified Carbon Paste Electrode

A gold nanoparticles modified carbon paste electrode (GN‐CPE) was used as a highly sensitive electrochemical sensor for determination of tyrosine (Tyr), dopamine (DA) and uric acid (UA) in phosphate buffer solution (PBS). The study and measurements were carried out by using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry methods. In DPV, the GN‐CPE could separate the oxidation peak potentials of DA and UA present in the same solution, though at the unmodified CPE the peak potentials were indistinguishable. The prepared electrode showed voltammetric responses with high sensitivity and selectivity for Tyr, DA and UA in optimal conditions, which makes it very suitable for simultaneous determination of these compounds. The calibration curves for Try, DA and UA were linear for the concentrations of each species. The proposed voltammetric approach was also applied to the determination of Tyr concentration in human serum as a real sample.     

磁场控制技术在微流控芯片中的应用*

磁场作为除了电场和力场之外的另一个有力的驱动和控制手段,由于不需与溶液接触即可实现对被分析物的操纵,极大降低污染的可能,近年来被越来越广泛地用于微流控芯片系统,尤其在细胞、病毒甚至单分子的捕获、分选以及操纵等方面显示出较大优势。本文综述了微流控芯片系统中磁场控制技术的最新进展,分别从理论分析,磁场加工技术、泵阀的实现,微流体控制和磁分离等方面介绍了该领域近几年的发展状况,并重点分析了微流控芯片磁场操控技术在临床分析和现场检测方面的应用,及其未来发展趋势和需解决的主要问题。     

Analytical Application of Pyramidal,Rodlike, and Spherical Gold Nanostructures: Simultaneous Detection of Ascorbic Acid and Uric Acid

Simultaneous detection of ascorbic (AA) and uric acid (UA) is developed at pyramidal (NP), rodlike (NR), and spherical (NS) gold nanostructures, due to their high electrocatalytic activities toward the oxidation of AA and UA. Unlike at bare gold electrode, the fouling resulted from the oxidized product of AA is eliminated at the nanostructured gold electrode. The voltammetric signals of AA and UA are completely separated with a potential difference of 216 mV, 158 mV and 195 mV, respectively, at the pyramidal, rodlike, and spherical gold surfaces. The experimental results reveal that solution pH effects the peak separation of AA and UA, acidic solution is more favorable for the simultaneous determination of AA and UA than neutral one, than alkaline one. The coexistence of a large excess of AA does not interfere with the voltammetric sensing of UA, vice versa. All the three kinds of nanostructured gold electrodes show excellent sensitivity, stability, selectivity, low detection limit, quick response and wide linear range in the repeated detection of AA and UA. The practical utility of the present nanostructured gold electrodes is demonstrating by determining the concentration of AA in fruit juice and UA in urine sample.     

基于等离子体技术制作微流控纸芯片及其在血糖检测中的应用研究

滤纸经十八烷基三氯硅烷(OTS)疏水化处理以后,用等离子体区域降解滤纸纤维表面的OTS疏水单分子层,使滤纸的局部区域恢复亲水性,得到具有亲疏水图案化的微流控纸芯片. 考察了等离子体处理时间对滤纸表面亲水性、亲水深度(水溶液由滤纸表层下渗至内部的纵向深度)的影响. 优化模具的设计,依据对滤纸亲水深度的不同需求,设计了两种PMMA-PDMS复合片的组合模具. 初步探讨了该亲疏水性变化过程的化学机理. 将制得的纸芯片用于人体全血中血糖含量的测定,线性范围为1.7～17.7 mmol·L^-1,可满足血液样品中血糖的测定.     

写字机器人绘制纸基微流控芯片便携检测Ca2+

纸基微流控芯片是一种纸质基底芯片,具有性能优良、价格低廉的优势,然而其制备技术多依赖专业昂贵的设备,限制了纸基微流控芯片的发展。该文采用成本低廉的家用写字机器人,将具有敏感特性的智能水凝胶绘制在纸质基底材料上,得到具有水凝胶阀门的纸基微流控芯片。以Ca2+为模型靶标,该纸基微流控芯片能实现不同浓度（0.1 ~ 50 mmol/L）Ca2+溶液的裸眼定量检测,并具有很好的易用性和重现性。同时采用ILX506 CCD传感器制作纸基微流控芯片的数字显示设备,以实现芯片测量结果的自动读取功能。该方法能快速便捷、低成本地制备多条纸基微流控芯片,为其普适化制备提供了新的研究思路,在发展中地区具有良好的推广前景。     

盖印法加工纸基微流控芯片及其应用

建立了一种盖印法加工纸基微流控芯片的方法。滤纸经烷基烯酮二聚体(AKD)的正己烷溶液浸泡,以三乙醇胺溶液为阻断试剂,用绘图软件设计芯片图案并制作光敏印章,用带有芯片图案的印章将阻断试剂盖印在滤纸表面。滤纸在105 ℃烘箱中加热10 min后,非盖印区域呈疏水性,盖印区域呈亲水性,从而形成液体流动通道。考察了疏水试剂浓度、阻断试剂的选择及配比、盖印分辨率等因素对纸芯片性能的影响。制得的纸芯片用于亚硝酸钠溶液的比色分析,获得良好的线性关系。该方法具有成本低廉、操作简便快速等特点,在制备廉价易普及的纸芯片方面有一定应用前景。