基于石墨烯修饰碳电极的铜离子印迹电化学传感器的制备与应用

以铜离子为模板,多巴胺为功能单体,采用电聚合法在石墨烯修饰碳电极表面成功制备对铜离子有高选择性和灵敏性的印迹电化学传感器。采用差分脉冲伏安法和循环伏安法对该印迹传感器的电化学行为进行详细研究。在优化检测条件下,该印迹电化学传感器的响应电流与铜离子浓度的负对数在5.0×10~(-6)~5.0×10~(-11)mol/L浓度范围内呈良好的线性关系,最低检测限为1.0×10~(-11)mol/L。该印迹电化学传感器成功用于实际水样中的微量铜离子分析。     

基于金纳米粒子及石墨烯量子点的四环素分子印迹电化学传感器研究

该文以四环素为模板分子,4-氨基苯硫酚(4-ATP)为功能单体,采用循环伏安法在金纳米粒子和石墨烯量子点复合材料修饰的玻碳电极表面电聚合分子印迹膜,制备四环素(TC)分子印迹传感器(MIPs/GQDs-AuNPs/GCE),并通过循环伏安法(CV)、电化学交流阻抗法(EIS)和线性扫描伏安法(LSV)等研究了其电化学响应性能。结果表明,该传感器对四环素具有良好的电流响应。在最佳实验条件下,TC氧化峰电流值与其浓度在2.0×10~(-8)～3.0×10~(-5) mol/L范围内呈良好的线性关系,相关系数为0.999 4,检出限为1.5×10~(-9) mol/L,加标回收率为97.9%～106%。该传感器稳定性好、响应灵敏、选择性高,具有良好的应用前景。     

磁性石墨烯修饰辛基酚印迹传感器制备及应用研究

以辛基酚(4-OP)为模板分子,多巴胺为功能单体,采用电聚合技术在磁性石墨烯修饰碳电极表面制备对辛基酚具有高选择性与灵敏性的印迹电化学传感器。采用循环伏安法(CV)和差分脉冲伏安法(DPV)对此印迹传感器的电化学性能进行详细表征;采用扫描电子显微技术对修饰电极的形貌进行表征。结果表明,此印迹电化学传感器对辛基酚具有良好的特异识别性能。采用 DPV 法考察了孵化时间和洗脱溶剂对印迹传感器性能影响,结果表明,最佳孵化时间为14 min。此印迹电化学传感器的响应电流(△IR )与辛基酚在5.0×10-6~5.0×10-9 mol/ L 范围内浓度的负对数(-lgC)呈良好的线性关系,线性方程为△IR ( mA)=-0.25lgC(mol/ L)+2.35,检出限为3.64×10-10 mol/ L (S/ N=3)。此印迹电化学传感器对辛基酚具有良好的选择性和灵敏性,成功用于实际水样中辛基酚的检测,回收率为96.0%~104.0%。     

碳纳米管修饰电极分子印迹传感器的制备及其对氧乐果的测定

以氧乐果为模板分子,邻苯二胺为功能单体,在碳纳米管修饰的玻碳电极表面通过电聚合方法制成氧乐果分子印迹聚合物膜,用无水乙醇洗脱后制备出对氧乐果有特异响应的电化学传感器。通过循环伏安法和电化学阻抗法对分子印迹传感器的电化学性能进行表征。以K_3Fe(CN)_6为探针,采用差分脉冲伏安法研究了该分子印迹传感器的分析性能,建立了氧乐果的间接测定方法。结果表明,K_3Fe(CN)_6的相对峰电流与氧乐果浓度在1.0×10~(-7)~2.0×10~(-6)mol/L范围内呈良好的线性关系,检出限为3.6×10~(-8)mol/L。     

盐酸普萘洛尔分子印迹电化学传感器的制备与研究

以盐酸普萘洛尔为目标模板分子,通过电聚合多巴胺,在多壁碳纳米管修饰的玻碳电极表面制备了对目标分子有特异响应的分子印迹电化学传感器.利用扫描电子显微镜、循环伏安法和差示脉冲伏安法对此传感器的表面形貌及性能进行了表征,并且优化了检测条件,研究了印迹传感器对模板分子及其结构类似物的选择性响应.结果表明:此传感器具有较好的选择性响应,而且碳纳米管的存在显著提高了传感器的灵敏度.盐酸普萘洛尔的浓度在0.20～100 μmol/L范围内与峰电流呈良好的线性关系;检出限为2.53×10-8 mol/L(S/N=3).此传感器还具有良好的稳定性和重现性.     

盐酸金霉素分子印迹电化学传感器的研制

构建了一种选择性检测盐酸金霉素(CTC)的分子印迹电化学传感器。在NaClO4溶液中,以邻氨基酚(OAP)为功能单体,盐酸金霉素(CTC)为模板,通过循环伏安法在玻碳电极表面上聚合制备了CTC印迹敏感膜(MIPs)。在含0.005 mol/L K3[Fe(CN)6]及0.1 mol/L KCl的磷酸盐缓冲液(PBS)中,应用差分脉冲伏安法(DPV)研究了传感器的响应性能。DPV峰电流差与CTC浓度在2.0×10!8~6.1×10!7mol/L范围内呈线性关系,检出限为1.5×10!8mol/L(3σ)。实验表明,用甲醇/H2SO4混合洗脱溶液可以使传感器再生,对CTC的测定具有良好的重现性,并具有良好的储存稳定性。传感器对于干扰物氯霉素及青霉素没有响应,结构相似的四环素、土霉素有微弱的响应,显示了良好的选择性。在牛奶和鸡肉实际样品中所测得的CTC加标回收率为86.4%~96.9%。与文献报道的CTC检测方法相比,本传感器具有低的检测限,操作简便,整个过程无需衍生化处理,响应快,成本低。     

盐酸阿霉素在玻碳电极上的电化学行为研究及分析应用

采用线性扫描伏安法和循环伏安法研究了盐酸阿霉素在玻碳电极上的电化学行为及电极反应机理,优化了测定盐酸阿霉素的各实验参数。结果表明,在0.01 mol/L的HCl溶液中,盐酸阿霉素在-0.40 V处出现(vs.SCE)一灵敏的还原峰,峰电流与其溶液浓度在5.0×10-8~1.0×10-6mol/L(r=0.999)和1.0×10-6~1.0×10-5mol/L(r=0.998)范围内呈良好的线性关系,检出限为1.0×10-8mol/L。并用循环伏安法研究了盐酸阿霉素的峰电流性质,发现电极反应属于准可逆过程,出现一对灵敏的氧化还原峰,体系属准可逆吸附波。利用盐酸阿霉素在玻碳电极的电化学行为建立的分析方法可用于盐酸阿霉素的质量监控及药代动力学研究。     

碳纳米管纳米分子印迹聚合物传感器的制备及对血液中葡萄糖的测定

以葡萄糖为模板分子,通过电聚合邻苯二胺,在多壁碳纳米管修饰的GC电极表面制备了一种对葡萄糖具有选择性响应的分子印迹聚合薄膜传感器,优化了制备方法。通过循环伏安法(CV)和交流阻抗法对该分子印迹传感器对葡萄糖的响应性能进行了表征。在最优实验条件下,该印迹电极能在6.0~560.0μmol/L浓度范围内对葡萄糖进行检测,检出限为8.0×10~(-7) mol/L,并可在其他物质存在下选择性识别葡萄糖。此传感器可用于血液中葡萄糖的测定,加标回收率为98.5%~103.3%。     

自组装碳纳米管-氯洁霉素分子印迹溶胶-凝胶电化学传感器研究

结合自组装技术, 采用电聚合方法在碳纳米管修饰金电极表面制备对氯洁霉素具有特异性识别位点的分子印迹溶胶-凝胶薄膜, 成功构建了一种新型印迹溶胶-凝胶电化学传感器. 通过循环伏安法(CV)、示差脉冲法(DPV)、安培计时法(I-t)和扫描电镜(SEM)表征了该印迹溶胶-凝胶膜的电化学性能和表面形貌. 结果表明, 该传感器具有良好的选择性和灵敏度, 氯洁霉素在多壁碳纳米管修饰的印迹溶胶-凝胶传感器上的响应明显提高. 该印迹溶胶-凝胶传感器对氯洁霉素的浓度响应线性范围为5.0×10^-7~8.0×10^-5 mol/L, 检出限为2.44×10^-8 mol/L. 该传感器被成功地用于人体尿液中氯洁霉素的分析测定.     

利巴韦林原位聚合分子印迹电化学传感器的研制

利用原位聚合分子印迹技术,以3-氨基苯硼酸(3-ABBA)为功能单体,利巴韦林(RIB)为目标分子,以硼酸和顺式二醇在不同酸碱度条件下可逆形成环内酯键为原理,在玻碳电极表面原位聚合形成利巴韦林分子印迹膜,研制了测定利巴韦林的分子印迹电化学传感器。采用循环伏安法(CV)和差分脉冲法(DPV)对印迹膜性能进行研究。DPV测试表明:在最优实验条件下,利巴韦林的浓度在5.0×10~(-8)~1.0×10~(-5)mol/L范围内与峰电流呈良好的线性关系,相关系数(r~2)为0.995 3,检出限(S/N=3)为1.5×10~(-8)mol/L。特异性实验表明制备的传感器对利巴韦林的选择性良好。该分子印迹电化学传感器可用于食品中利巴韦林的检测。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.