Plant-mediated Synthesis of Silver and Gold Nanomaterials by Biomass-based Reduction and Their Potential Applications

贵金属纳米材料因其具有独特的催化和光学性能而得到广泛重视，其制备与应用已成为当今纳米技术领域中的一个研究热点。相对于传统的物理法和化学法，近年来出现的基于微生物或植物的生物还原法，具有成本低、绿色环保、纳米材料稳定性高等优点，成为贵金属纳米材料具有发展前景的新颖制备方法。在原材料方面，相比微生物繁琐的筛选与培养过程，植物及其提取液的获得和使用更加简便，得到了一定的关注。然而，目前有关植物及其提取液制备贵金属纳米材料的研究更多地集中在简单的条件实验和纳米材料的表征等，很多重要的基础问题还远未搞清楚，例如：贵金属纳米材料形貌和颗粒粒度的控制仍较为有限，植物及其提取液的工艺路线和还原反应器，以及还原...Noble metal nanomaterials have attracted extensive attention owing to their unique catalytic and optical properties. Therefore, their preparation and application have become one of research highlights in the field of nanotechnology. Compared with the traditional physical and chemical methods of synthesizing metal nanomaterials, the bioreduction methods based on microorganisms or plants have emerge...学位：工学博士院系专业：化学化工学院化学工程与生物工程系_工业催化学号：1922005140310

微生物吸附-化学还原法合成金钯纳米线机理研究

采用微生物吸附-化学还原法,以大肠杆菌(ECCs)为模板、十六烷基三甲基溴化铵(CTAB)为保护剂、抗坏血酸(AA)为还原剂制备金钯纳米线(Au-PdNWs),考察不同金钯摩尔比对合成金钯纳米材料的影响,并通过SEM、TEM、XRD等技术进行了表征,研究其形成机理。结果表明,吸附还原作用使ECCs在短时间内还原生成了少量Pd(0)和Au(0),大量的钯离子和金离子聚集在ECCs表面周围;还原剂AA的加入使ECCs表面成为优先成核位点,菌体表面基团与晶核相互作用阻止其迁移;在CTAB的作用下,菌体表面的纳米颗粒逐渐形成链状纳米中间结构,中间结构通过Ostwald熟化作用进一步形成Au-Pd纳米线。通过ECCs和CTAB协同作用,有利于一维纳米结构的生长。福建省教育厅中青年教科研项目(JAT171117);;莆田市工业科技类科研项目(2016G2020

Preparation of Au nanowires based on synergistic action of Pichia pastoris cells and surfactant

在毕赤酵母-十六烷基三甲基溴化铵(CTAb)的协同作用下利用抗坏血酸(AA)还原氯金酸(HAu Cl4)制备Au纳米线,采用SEM、TEM、HrTEM及SAEd等手段对Au产物进行表征,结果表明产物为带有分支结构的Au纳米线,纳米线在分叉处的晶型是连续的,具有多晶结构的特征。研究发现,菌体-HAu Cl4的相互作用对于后续纳米线的生成过程至关重要,部分Au(Ⅲ)可吸附在菌体表面并被还原为很小的Au(0),在AA加入后纳米线的生成过程中起到了晶种的作用。菌体-HAu Cl4作用时间过长会导致菌体表面生成的Au(0)趋于稳定,不利于进一步生长为Au纳米线。菌体-表面活性剂的协同作用导致分支结构的多晶Au纳米线的生成。Au nanowires(Au NWs) were obtained by the reduction of HAu Cl4 with ascorbic acid(AA) under the synergistic action between microorganism(Pichia pastoris cells, PPCs) and hexadecyltrimethylammonium bromides(CTAB).SEM, TEM, HRTEM and SEAD were used to characterize the shape and structure feature of the Au nanoproducts.The results showed the Au NWs were hierarchically branched polycrystal and the interfaces of the branched positions were continuous in lattice.The interaction process between the microorganism and CTAB was researched and it was found that Au(0) could be formed on the PPCs surface, which acted as the seeds for the formation of Au NWs after AA addtion.Without the interaction process between the microorganism and CTAB, the Au nanoparticles instead of nanowires were acquired.Too long time adsorption between PPCs and HAu Cl4 led to stable Au(0) on the microorganism surface, which was also unfavorable for the subsequent growth of Au NWs.The synergistic action between microorganism and CTAB resulted in the formation of Au NWs with hierarchically branched polycrystalline structure.国家自然科学基金项目(21406186)~

Clinical significance of RRM1, CDX2 expression in different gastric mucosa lesions

目的探讨核苷酸还原酶亚单位M1（ribonucleotide reductase M1,RRM1）、尾型同源盒转录因子2（caudal-related homeobox transcription factor 2,CDX2）在不同胃黏膜组织中的表达,并分析其与胃癌发生发展及预后的关系。方法选取中国人民解放军第一七五医院病理科保存的组织蜡快240例,其中胃癌90例、高级别上皮内瘤变30例、低级别上皮内瘤变30例、肠上皮化生30例、浅表性胃炎30例、正常胃黏膜30例,采用S-P免疫组化方法检测6类不同胃黏膜组织RRM1、CDX2表达,进行临床病理相关性分析。结果正常胃黏膜、浅表性胃炎、肠上皮化生、低级别上皮内瘤变、高级别上皮内瘤变和胃癌中RRM1的阳性表达分别为40.0%、66.7%、33.3%、83.3%、83.3%、86.7%,胃癌、高级别上皮内瘤变、低级别上皮内瘤变组RRM1的阳性表达率均显著高于正常胃黏膜组与肠上皮化生组（P〈0.01）,亦高于浅表性胃炎组（P〈0.05）。CDX1的阳性表达分别为16.7%、0%、63.3%、33.3%、76.7%、61.1%,高级别上皮内瘤变、肠上皮化生、胃癌组的CDX2阳性表达率均显著高于浅表性胃炎组与正常胃黏膜组（P〈0.01）,高于低级别上皮内瘤变组（P〈0.05）。240例不同胃黏膜病变中,RRM1与CDX2之间表达呈正相关（rs=0.196,P=0.002）,90例胃癌中RRM1与CDX2之间呈正相关关系（rs=0.223,P=0.034）;RRM1、CDX2表达与肿瘤分化程度密切相关（P〈0.05）,CDX2表达与肿瘤浸润深度、淋巴结转移、TNM分期密切相关（P〈0.05）。结论 RRM1、CDX2表达均与胃癌的发生发展及预后有关,均可作为较为理想的肿瘤标志物,用于胃癌的早期诊断和转移的预警。Objective To explore the expression of ribonucleotide reductase M! （RRM1）and caudal- related homeobox transcription factor 2 （CDX2） in different gastric mucosa lesions and evaluate its relationship with the occurrence, development and prognosis of gastric cancer. Methods A total of 240 cases were selected from Department of Pathology of 175th Hospital of PLA, including 90 cases of gastric cancer,30 cases of highgrade intraepithelial neoplasia,30 cases of lowgrade intraepithelial neoplasia,30 cases of intestinal metaplasia, 30 cases of superficial gastritis, 30 cases of normal gastric mucosa. Expression of RRM1 and CDX2 was detected with immunohistochemistry SP method. Results The frequency of RRM1 expression were 86.7% ,83.3% and 83.3% in gastric cancer group, high - grade intraepithelial neoplasia group and low - grade intraepithelial neoplasia group, respectively. The frequencies were all higher than that in superficial gastritis group （66.7% ,P 〈0.05） and that in intestinal metaplasia group （33.3% ,P 〈0.01 ）. The frequency of RRM1 expression was higher in superficial gastritis group than that in intestinal metaplasia group（ P 〈 0.05 ）. The frequency of CDX2 expression were 76.7% ,63.3% and 61.1% in high - grade intraepithelial neoplasia group, intestinal metaplasia group and gastric cancer group, respectively. The frequencies were all higher than that in low - grade intraepithelial neoplasia group （33.3% ,P 〈 0.05 ） and that in superficial gastritis group （0%, P 〈 0.01 ）. In 240 cases of different gastric mucosa lesions, RRM1 expression was positively correlated with CDX2 expression（rs = 0. 196, P = 0. 002）. In 90 cases of gastric cancer, RRM1 expression was positively correlated with CDX2 （ r = 0. 223, P = 0. 034）. The expression of RRM1 and CDX2 were related with the differentiation degree （ P 〈 0.05 ）. CDX2 expression was related with the tumor invasion depth, TNM stages and the lymph node metastasis （P 〈 0.05）. Conclusion The expression of RRM1 and福建省教育厅B类科技基金资助项目（JB12319

Preparation of stearic acid-modified ZnO nanomaterials and their photocatalytic properties under visible light irradiation

以硫酸锌和氢氧化钠为原料,硬脂酸为修饰剂,采用一步沉淀法制备出硬脂酸修饰的纳米znO,并对可见光光催化性能进行了研究。借助Xrd、TEM、fTIr、uV-VIS等测试手段对硬脂酸修饰的纳米znO进行表征。结果表明,硬脂酸修饰的纳米znO分散比较均匀,硬脂酸与纳米氧化锌之间形成了化学键,而且硬脂酸修饰后,纳米znO更易被可见光激发,当甲基橙初始浓度为5 Mg/l,硬脂酸修饰的纳米znO投加量为10 Mg/l,光照时间70 MIn,硬脂酸修饰的纳米znO对甲基橙的降解率达到82.3%。Nanometer stearic acid-modified ZnO was prepared with one step precipitation method using zinc sulfate and sodium hydroxide as raw material,and its photocatalytic properties under visible light irradiation was also studied.X-ray diffraction,Transmission electron microscope,Infrared spectrometer and ultraviolet visible spectrophotometer were used to characterize the doped nanometer ZnO.The results showed nanometer stearic acid-modified ZnO dispersed well and chemical bonds formed between stearic acid and ZnO.Furthermore,nanometer stearic acid-modified ZnO was easier to be irradiated by visible light than that without any modification.Additionally,the photocatalytic properties of stearic acid-modified ZnO were finally investigated with methyl orange solution as the degradation model.The degradation rate of methyl orange can reach 82.3% under the following conditions: the original concentration of methyl orange of5 mg /L,light catalyst dosage of 10 mg /L and illumination time of 70 min.国家自然科学基金资助项目(21206079;21106117;21036004

钯原子修饰的金纳米颗粒乙醇氧化电催化剂（英文）

钯催化剂对碱性溶液的乙醇电催化氧化反应表现较好的催化活性.本文通过简单的化学沉积法,将钯原子成功修饰到金纳米颗粒表面,制备的催化剂对乙醇电催化氧化反应表现出比钯更好的催化性能.研究发现,钯原子不均匀地覆盖在金核表面,部分金原子暴露在外层.制备的催化剂的峰电流密度是钯催化剂的4.6倍,起始电势低100 m V.该催化剂较好的催化性能可能归因于金核的电子效应和表面双功能电催化反应机制.support from Research Grant Council(No.26206115) of the Hong Kong Special Administrative Region;;Scientific Research Fund of Zhejiang Provincial Education Department(No.Y201840545

芳樟叶浸出液还原制备对硝基苯酚加氢银催化剂

采用芳樟叶浸出液,通过原位还原和等体积浸渍的方法制备负载型纳米银催化剂,并以对硝基苯酚(4-NP)加氢反应为模型反应,考察催化剂载体,焙烧条件等对负载型纳米银催化剂性能的影响,并采用扫描电镜(SEM),热重分析(TG)和红外光谱(FT-IR)等表征手段对催化剂进行表征。结果表明,以TiO_2为载体制备的纳米银催化剂具有较好的催化活性;植物还原法制备的催化剂表面纳米银颗粒较小((7.3±2.4)nm),催化效果较好。当体系中Ag与4-NP的物质的量之比为1:230时,完全反应时间小于或等于10 min。对催化剂进行一定条件的焙烧处理,能在一定程度上提高催化剂的活性和重复使用性,将催化剂于400℃下焙烧1h,催化活性最佳:将催化剂于400℃下焙烧2h,催化剂重复使用性最好。对芳樟叶浸出液与银的作用机理进行初步研究,表明劳樟叶浸出液中的杂环化合物能通过羰基与银络合,从而起到防止催化剂表面纳米银颗粒团聚的作用

Expression and clinical significance of RRM1,CDX2 in gastric cancer tissues

目的探讨RRM1、CDX2在胃癌组织中的表达,并分析其与胃癌侵袭与转移的关系。方法选取90例术前未行放化疗的胃癌石蜡标本及与其对应正常胃黏膜蜡标本30例,采用SP免疫组化方法检测RRM1和CDX2在两种组织中表达情况,分析二者表达与分化程度、浸润深度、淋巴结转移、TNM分期之间的关系。结果 （1）RRM1、CDX2在胃癌中的阳性表达率均显著高于正常胃黏膜组（86.7%vs 40.0%,P〈0.01;61.1%vs 16.7%,P〈0.01）。（2）90例胃癌中,RRM1与CDX2二者之间呈正相关关系（r_s=0.223,P=0.034）;RRM1、CDX2表达与分化程度密切相关（P〈0.05）,CDX2表达与浸润深度、淋巴结转移、TNM分期密切相关（P〈0.05）,RRM1表达与浸润深度、淋巴结转移、TNM分期无相关（P〉0.05）。结论 RRM1、CDX2可作为较为理想的肿瘤标志物,用于胃癌的诊断和预后的预警。Objective To explore the expression of RRM1 and CDX2 in gastric cancer tissues and its relationship with invasion and metastasis of gastric cancer. Methods Expression of RRM1 and CDX2 was detected in 90 cases of gastric cancer without preoperative chemoradiotherapy and 30 cases of normal gastric mucosa using immunohistochemistry SP method. The relationships of RRM1 and CDX2 expression with differentiation degree,tumor invasion depth,TNM stage and lymph node metastasis were analyzed. Results（1）The positive expression rates of RRM1 and CDX2 were both significantly higher in gastric cancer tissues than in those of normal gastric mucosa（86. 7% vs 40. 0%,P 〈 0. 01; 61. 1% vs 16. 7%,P 〈 0. 01）.（2） The expression of RRM1 in 90 cases of gastric cancer was positively correlated with CDX2（ r_s= 0. 223,P = 0. 034）. The expression of RRM1 and CDX2 was related with differentiation degree（ P〈 0. 05）. The expression of CDX2 was related with tumor invasion depth,TNM stage and lymph node metastasis（ P 〈 0. 05）. The expression of RRM1 was not related with tumor invasion depth,TNM stage,lymph node metastasis（ P 〉 0. 05）. Conclusion RRM1 and CDX2 can be used as ideal tumor markers in diagnosis of gastric cancer and prognosis.福建省教育厅B类科技基金资助项目（JB12319

生物法制备纳米银溶胶的稳定性

利用生物还原法制备纳米银溶胶,借助于UV-Vis表征技术对其热稳定性和化学稳定性进行考察。结果表明:生物法制备的纳米银溶胶在100℃下加热6h,UV-Vis谱图未发生明显变化;H+和具有高价阳离子的电解质对其稳定性的影响明显;OH-对银溶胶的稳定性影响相对较弱。生物法制备的纳米银溶胶在热稳定性、化学稳定性方面均略优于柠檬酸三钠法制得的银溶胶

贵金属纳米材料生物还原制备技术的研究进展

综述了国内外利用生物还原技术制备贵金属纳米材料及贵金属催化剂的研究进展,并展望了该研究领域的发展方向