基于碳量子点修饰纳米硅胶荧光猝灭-恢复测定粮食样品中还原型谷胱甘肽

制备了碳量子点修饰硅胶(Si O_2@CDs),经过Cu~(2+)处理后,根据Si O_2@CDs荧光强度恢复程度与还原型谷胱甘肽(GSH)成正比的现象,建立了基于Si O_2@CDs荧光猝灭-恢复测定GSH的新方法.考察了溶液p H值和反应时间对检测体系的影响.在最佳的实验条件下,GSH浓度在0.2×10~(-6)~8.0×10~(-6)mol/L范围内与Si O_2@CDs的荧光恢复程度呈良好线性,检出限(3σ)为0.03×10~(-6)mol/L.用于粮食样品中GSH的检测,回收率在90.0%~115.2%之间.     

一种新型连续检测镉离子和焦磷酸阴离子的逻辑门荧光传感器及其细胞成像研究

设计并合成了一种基于8-羟基喹啉(8-HQ)的连续检测Cd~(2+)和焦磷酸阴离子(PPi)的荧光传感器L.在传感器L的DMSO/H2O(V/V=1/1,0.01mol/L,Hepes-HClbuffer,pH=7.20)溶液中加入Cd~(2+)后导致荧光发射峰(Em=537 nm)猝灭,检测限低至5.87×10~(-8) mol/L.通过Job's曲线图和质谱验证传感器L和Cd~(2+)离子之间以1∶1化学计量比结合,结合常数为4.38×10~4 L/mol.复合传感器L-Cd~(2+)体系具有通过配体置换法对PPi高度选择性检测性能. L可以作为一种逻辑门荧光传感器检测Cd~(2+)和PPi.传感器L可以用于对活细胞中的Cd~(2+)和PPi的荧光成像.     

基于纳米金增敏的双酚A二氧化钛凝胶分子印迹电化学传感器的制备及应用

以纳米金(Au NPs)为增敏材料,双酚A(BPA)为模板分子,结合表面溶胶凝胶法和自组装法,制备了BPA纳米金-Ti O_2凝胶分子印迹电化学传感器。利用扫描电子显微镜和能谱对Au NPs进行了表征,利用红外光谱仪对Ti O_2凝胶、BPA以及BPA印迹Ti O_2凝胶进行表征。在最优条件下,该传感器对BPA在1.0×10~(-8)~1.0×10~(-5)mol/L浓度范围内具有良好的线性关系,线性相关系数为0.995,检测限为0.6×10~(-8)mol/L,并将该分子印迹传感器应用于实际样品中BPA的分析检测,其回收率为97.4%~103%。     

酪胺修饰石墨烯量子点检测血清中游离胆固醇

以柠檬酸为原料合成具有模拟过氧化氢酶活性的石墨烯量子点(GQDs),经酪胺修饰的GQDs(TYR-GQDs)可以将过氧化氢还原成羟基自由基,通过酚羟基之间的交联聚集,GQDs的荧光被猝灭。由于胆固醇氧化酶可以催化胆固醇氧化生成H_2O_2,因此,基于TYR-GQDs建立了一种检测胆固醇的荧光传感器。在pH=7.4的条件下,TYR-GQDs的荧光猝灭率与胆固醇浓度(2.67×10~(-8)～2.67×10~(-3)mol/L)的对数呈良好的线性关系,检出限为9.32×10~(-9)mol/L。干扰实验表明,该荧光传感器对胆固醇具有高度的选择性,可以用于人体血清中游离胆固醇的检测,加标回收率为96.55%～100.14%。     

水介质中二甲基姜黄素脂质体对金属离子的荧光识别

通过薄膜分散法制备二甲基姜黄素(ASC-J9)脂质体,其粒径分布均匀且在水中的分散效果好,平均粒径为145. 7 nm,分散系数为0. 361。将ASC-J9脂质体作为水溶性的荧光探针,通过荧光猝灭法可选择性识别Fe~(3+)、Fe~(2+)及Cu~(2+)。经过条件筛选得到最佳荧光测试条件为:ASC-J9脂质体浓度为5. 0×10~(-5)mol/L,平衡时间5 min,测试温度25℃。由Job's曲线和荧光滴定结果判断该探针与Fe~(3+)和Cu~(2+)的络合比均为1∶1,与Fe~~(2+)的络合比为2∶1; Stern-Volmer方程判断该荧光猝灭类型为静态猝灭,结合常数分别为KFe(Ⅲ)=9. 63×10~4L/mol,KFe(Ⅱ)=3. 65×10~5L/mol,KCu(Ⅱ)=2. 32×10~5L/mol;该识别体系检测快速、灵敏度高,对Fe~(3+)、Fe~(2+)、Cu~(2+)的线性范围分别为:5. 0×10~(-7)~3. 0×10~(-5)、5. 0×10~(-7)~1. 75×10~(-5)、5. 0×10~(-7)~2. 5×10~(-5)mol/L,检出限分别为6. 41×10~(-7)、3. 28×10~(-7)、5. 08×10~(-7)mol/L。     

基于HRP-H_2O_2-OPDA发光体系的流感病毒H1N1酶联免疫传感器

制备了一种基于HRP-H_2O_2-OPDA发光体系的流感病毒H1N1酶联免疫传感器。利用流感病毒H1N1表面的HA(血球凝集素)蛋白与糖蛋白能有效结合的特性,选择辣根过氧化物酶(HRP)作为生物标记物直接标记在流感病毒的表面,HRP能有效催化H_2O_2-邻苯二胺(OPDA)体系产生灵敏的显色反应和荧光效应。实验对HRP孵化时间、H_2O_2-OPDA催化反应时间等参数进行了优化。结果表明,该酶联免疫传感器对流感病毒H1N1检测的动态响应范围为0.0001~0.5μg/m L,检出限为50 pg/m L(3σ)。其他亚型病毒和干扰蛋白对该传感器的干扰较小,表现出良好的选择性。所构建的方法可为其它流感病毒及其它抗原的检测提供参考。     

过氧化氢检测用荧光探针的设计、合成及性能

基于逆向合成分析的方法,以水杨醛吖嗪作为传感产物,设计合成了一种用于检测H_2O_2的"开启式"荧光探针。在室温条件下向2-甲酰基苯基硼酸频哪醇酯中加入过量水合肼,通过一步反应和低成本合成,得到一种含硼氮杂环化合物。经X-射线单晶衍射确认此化合物和H_2O_2的反应产物为水杨醛吖嗪,因此达到检测溶液/薄膜中H_2O_2的目的。在溶液含水量为90%,酸碱度为中性的条件下,H_2O_2浓度从0增加到100μmol/L,通过光谱仪测得探针分子荧光增强约120倍,同时在含有其它氧化物的溶液中,荧光响应微弱。该探针具有优异的选择性和高灵敏度(2. 1×10~(-7)mol/L)。     

基于聚合物点的电致化学发光生物传感器用于葡萄糖检测

羧基功能化的聚[(9,9-二辛基芴基-2,7-二基)-co-(1,4-苯并-{2,1′,3}-噻二唑)]聚合物点(PFBT-COOH)在无外加共反应试剂的条件下具有高的电致化学发光(ECL)信号,且过氧化氢(H_2O_2)对其ECL具有高效猝灭作用。采用PFBT-COOH修饰玻碳电极,进一步交联葡萄糖氧化酶(GOD)以构建酶传感器(GOD/PFBT-COOH/GCE)。随着检测底液中葡萄糖浓度的增加,葡萄糖在GOD催化下原位产生的H_2O_2量增加,导致传感器的ECL信号逐渐减弱,从而实现葡萄糖的准确、快速、灵敏检测。此方法测得葡萄糖的线性范围为1.0×10~(-7)～3.0×10~(-3) mol/L,检出限为3.0×10~(-8) mol/L。血清样品中葡萄糖的加标回收率为98.5%～106%。该策略为酶传感器的构建提供了新思路,为葡萄糖的检测提供了新方法。     

一种基于香豆素骨架的荧光化学传感器于水溶液中实现对Al~(3+)和焦磷酸根(PPi)的连续识别

合成了一种新型的荧光化学传感器(E)-N'-(3-((双(吡啶-2-亚甲基)氨基)甲基)-2-羟基-5-甲基亚苄基)-7-(二乙氨基)-2-氧代-2H-色烯-3-甲酰肼(1),并通过~1HNMR、~(13)CNMR和ESI-MS对其结构进行表征,利用紫外/荧光分光光度法研究了传感器1的传感性能.结果表明:传感器1于水中对Al~(3+)表现出明显的荧光增强响应,而配合物1-Al~(3+)对PPi表现出明显的荧光淬灭响应.传感器1对Al~(3+)和焦磷酸根(PPi)的检测限分别为0.26和0.1μmol/L,配位比均为1∶1.配位机理通过荧光滴定、核磁滴定和高分辨质谱进行了证实,另外传感器1的有效测试pH范围是2～10,且循环响应测试可达4次.     

基于Fe_3O_4@Ag壳核结构磁性纳米复合物的杀螟硫磷电化学传感

制备了一种核壳结构的磁性纳米粒子Fe_3O_4@Ag,将该纳米粒子通过壳聚糖(CS)修饰到玻碳电极(GCE)表面,构建了杀螟硫磷电化学传感器,研究了传感器的电化学和电催化行为,建立了杀螟硫磷测定的电分析新方法。应用透射电镜和紫外可见光谱对Fe3O4@Ag纳米粒子进行表征。研究发现,该传感器对杀螟硫磷有很好的电催化作用,其峰电流与浓度在1.74×10~(-7)~3.27×10~(-4)mol/L范围内呈线性关系,相关系数为R~2=0.9871,检出限为5.7×10~(-8)mol/L(S/N=3)。该传感器有望用于杀螟硫磷的检测。     

利用salen型荧光探针测定Cr3+

研究了salen型席夫结构的荧光探针N,N’-二(2-羟基-1-萘甲醛)-l,2-苯二胺(NAPPDIH)对Cr3+的响应。Cr3+能够使该探针的荧光猝灭。研究表明,在pH3.5(乙酸胺-盐酸)和DMSO/H2O(V/V,8:2)的条件下,8.0×10-6 mol/L的Cr3+可以导致NAPPDIH 65%的荧光猝灭。并且,Cr3+的浓度在5.0×10-7～8.0×10-6 mol/L的范围内,与荧光强度的变化值呈良好的线性关系,检出限为3.7×10-7 mol/L。方法可用于直接检测水样中的Cr3+。     

Determination of Cr3+, CrO42-, and Cr2O72- in environmental matrixes by high-performance liquid chromatography with diode-array detection (HPLC-DAD)

A high-performance liquid chromatographic method with diode array detection (HPLC-DAD), based on chelation with ammonium pyrrolidinedithiocarbamate (APDC), has been developed for the determination of chromium species. Determination of Cr3+, CrO42-, and Cr2O72- was performed for standards and synthetic environmental matrixes. This method is robust, rugged, and can be used for rapid routine determination of chromium species with high precision and reliability. Sample pretreatment is simple. The method is capable of discriminating not only between Cr(III) and Cr(VI) but also between the chemical forms of Cr(VI) - CrO42- and Cr2O72-. By analysis of numerous samples the method has been shown to be selective, sensitive, and free from matrix interference, which is crucial for the determination of chromium species in difficult-to-analyze environmental matrixes. This method has been validated by means of an interlaboratory study. Although different speciation techniques were used during this study, there was good agreement between results from the two laboratories. The method detection limits were 7 and 4 mg L(-1) for Cr3+ and Cr2O72-, respectively. Recoveries of the analytes from spiked samples were 98% and 100% for Cr3+ and Cr2O72-, respectively. Both were based on a 10-mL sample volume spiked with 0.4 mg L(-1) chromium.     

Ligand effect on the kinetics of hydroperoxochromium(III)-oxochromium(V) transformation and the lifetime of chromium(V)

A macrocyclic superoxochromium complex L(2)(H(2)O)CrOO(2+)(L(2)=meso-Me(6)-[14]aneN(4)) is generated from L(2)Cr(H(2)O)(2)(2+) and O(2) with k(on)=(2.80 +/- 0.07)x 10(7) M(-1) s(-1). One-electron reduction of L(2)(H(2)O)CrOO(2+) produces a transient hydroperoxo complex that readily undergoes intramolecular conversion to L(2)Cr(v), k(1)= 1.00 +/- 0.01 s(-1) in acidic aqueous solutions, and 0.273 +/- 0.010 s(-1) at pH >7, with an apparent pK(a) of 5.9. The decay of L(2)Cr(v) in the pH range 1.3-6.2 obeys the rate law, -d[L(2)Cr(v)]/dt= (0.0080 (+/- 0.0049)+ 8.19 (+/- 0.13)[H(+)])[L(2)Cr(v)]. Both the kinetics of formation and lifetime of L(2)Cr(v) are significantly different from those for the closely related [14]aneN(4) complex. The X-ray structure of the parent Cr(iii) complex, [L(2)Cr(H(2)O)(2)](ClO(4))(3).4H(2)O, shows that the macrocyclic ligand adopts the most stable, "two up-two down" configuration around the nitrogens.     

流动注射胶束电化学发光测定过氧化氢的研究

建立了一种简易、快速检测过氧化氢的流动注射电化学发光法。本法基于铂丝阳极在 1.3 V(vs.Ag Cl/Ag)时 ,在含有 Na2 CO3 -Na HCO3 缓冲溶液的 KCl支持电解质中现场产生试剂 ,当注入过氧化氢溶液后即产生电化学发光。加入 Triton X-10 0形成的胶束能增强这一体系的发光强度。该法测定过氧化氢的线性范围为 1.0×10 -7～ 1.0× 10 -5 mol/L,对 4.0× 10 -7mol/L的过氧化氢进行 11次测定的相对标准偏差为 2 .6%。用这一方法对雨水中的过氧化氢进行了测定 ,结果满意。     

氯化血红素模拟过氧化物酶高效液相色谱柱后衍生法测定过氧化氢和水溶性有机过氧化物

研究了氯化血红素（Ｈｅｍｉｎ）模拟辣根过氧化物酶（ＨＲＰ），对羟基苯乙酸（ＰＨＰＡＡ）作 底物，高效液相色谱（ＨＰＬＣ）柱后衍生荧光法测定Ｈ２Ｏ２和水溶性有机过氧化物的方法。采用 Ｈｅｍｉｎ作催化剂柱后衍生反应的最佳ｐＨ值约为１１，与荧光检测ｐＨ值一致，使得以往ＨＰＬＣ 柱后衍生方法所需的高压泵从３台减少到２台，而一些不能作为ＨＲＰ底物的羟烷基过氧化 物在ｐＨ值≥１０的溶液中迅速水解为Ｈ２Ｏ２从而得到测定。优化了测定Ｈ２Ｏ２和甲基过氧化 氢（ＣＨ３ ＯＯＨ， ＭＨＰ）的条件。最佳条件下 Ｈｅｍｉｎ方法测定 Ｈ２Ｏ２的检测限为 ９．０ × １０－９ ｍｏｌ／Ｌ， 测定 ＭＨＰ的检测限为 ２．０ × １０－７ ｍｏｌ／Ｌ。     

Incorporation of flow injection analysis or capillary electrophoresis with resonance Rayleigh scattering detection for inorganic ion analysis

Resonance Rayleigh scattering (RRS) has been explored as a detection (RRSD) technique for capillary electrophoresis (CE) or flow injection analysis (FIA) of inorganic ions. The detection was achieved through a scattering probe of ion-association complex formed from rhodamine B (Rh B) and iodine. The probe scatters strongly at 630 nm when oxidants such as Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) present in a mixed solution of Rh B and iodide. The scattering disappears once iodine is reduced by reductants. Oxidant or reductant species in a sample can thus be detected by positive or negative RRS signal. To verify the RRSD, FIA-RRSD was first constructed and continuous measurement of testing samples containing Cr(2)O(7)(2-), MnO(4)(-) and/or ClO(-) was performed. The detection limits reached a level of decade nM and a linear range was found between peak height and concentration at the range of 0.255-2.04microM for Cr(2)O(7)(2-), 0.158-3.16microM for MnO(4)(-), and 1.18-9.43microM for ClO(-), with linear regression coefficients of all above 0.99. The run-to-run relative standard deviation of peak height was less than 3% (n=6). CE-RRSD was then set up and studied, using a capillary of 75microm i.d.x33cm filled with a running buffer of 50mM citrate and 25mM Tris (pH 3.32) and worked under -12kV at room temperature. The CE eluent was at-line conducted into a stream of rhodamine B and iodine flowing inner a wide tube by plugging the capillary outlet into the wide tube. Different mixtures prepared from Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) were successfully separated and detected by the CE-RRSD.     

基于石墨烯-壳聚糖-辣根过氧化物酶的H2O2生物传感器的研制

制备了石墨烯-壳聚糖(GR-CS)纳米复合材料,并将之与辣根过氧化物酶(HRP)混合,构建了基于石墨烯-壳聚糖-辣根过氧化物酶的生物传感器(GR-CS-HRP/GC)。探针及循环伏安研究表明,该界面具有优异的电子传导能力、较大的比表面积和良好的生物相容性,对H2O2的还原显示出较好的电催化活性,在工作电位为-0.2 V,0.05 mol/L的磷酸盐缓冲盐溶液(PBS,pH 6.8)中,该酶传感器对过氧化氢响应灵敏度高,检测范围宽,测定H2O2的线性范围为5.0×10-7～2×10-3mol/L(相关系数为0.998)。检出限为2.0×10-7mol/L(S/N=3)。并且表现出良好的稳定性和高选择性。该电极用于实际样品中H2O2的测定,结果令人满意。     

Synthesis and structure of a bismuth(III)/chromium(VI) oxo cluster containing a Bi4Cr4O12 core

Bismuth(III) compounds containing the Kl?ui's oxygen tripodal ligand [CpCo{P(O)(OEt)(2)}(3)](-) (L(OEt)(-)) have been synthesized, and their interactions with dichromate in aqueous media were studied. The treatment of Bi(5)O(OH)(9)(NO(3))(4) with NaL(OEt) in water afforded [L(OEt)Bi(NO(3))(2)](2) (1), whereas that of BiCl(3) with NaL(OEt) in CH(2)Cl(2) yielded L(OEt)BiCl(2) (2). Chloride abstraction of 2 with AgX afforded [L(OEt)BiX(2)](2) [X(-) = triflate (OTf(-)) (3), tosylate (OTs(-)) (4)]. In aqueous solutions at pH > 4, 4 underwent ligand redistribution to give the bis(tripod) complex [(L(OEt))(2)Bi(H(2)O)][OTs] (5). The treatment of 4 with Na(2)Cr(2)O(7) in acetone/water afforded the Bi(III)/Cr(VI) oxo cluster [(L(OEt))(4)Bi(4)(μ(3)-CrO(4))(2)(μ(3)-Cr(2)O(7))(2)] (6) containing a unique Bi(4)Cr(4)O(12) oxometallic core. Compound 6 oxidized benzyl alcohol to give ca. 6 equiv of benzaldehyde. The reaction between 2 and CrO(3) yielded [L(OEt)Bi(OCrO(2)Cl)](2)(μ-Cl)(2) (7). The crystal structures of complexes 4-7 have been determined.     

间羧基偶氮羧光度法测定痕量铬的研究

研究了间羧基偶氮羧与Cr2 O2 -7的褪色反应 ,建立了一种新的测定痕量Cr(VI)的光度方法 .发现其在高氯酸介质中具有高灵敏的褪色反应 ,摩尔吸收系数达到 3 .5× 10 6L/mol·cmCr(VI)量在 0～ 48μg范围内符合比尔定律     

流动注射-鲁米诺-高碘酸钾-过氧化氢体系的化学发光行为及其应用

详细研究了流动注射－鲁米诺－高碘酸钾－过氧化氢体系化学发光行为，给出了反应的最佳条件。拟定了一种化学发光测定过氧化氢的新方法。方法的检测限为３．０Ｘ１０－８ｍｏｌ／ＬＨ２Ｏ２；线性范围为２．０×１０－７～６．０×１０－４ｍｏｌ／Ｌ。评价了该体系的应用前景。