金纳米棒对SPR生物传感器灵敏度的增强效应

研究不同长径比的金纳米棒对表面等离子体共振(SPR)生物传感器灵敏度的增强效应.利用晶种生长法合成不同长径比的金纳米棒,并对其形貌、光学性质进行表征.采用双抗体夹心法,以金纳米棒 与羊抗人IgG的偶联体作为第二抗体,利用实验室自行研制的波长调制SPR生物传感器对人IgG进行测 试.实验结果表明:不同长径比的金纳米棒...     

基于金纳米棒的DNA杂交检测

金纳米棒具有独特的光学性质与良好的生物适应性,在生物医学领域得到了日益广泛的应用.利用种子生长法,通过改变表面活性剂十二烷基二甲基苄基氯化铵(BDAC)的浓度所制备的8种不同长径比(AR)的金纳米棒,具有不同位置的纵向表面等离子共振(SPR)峰.在金纳米棒和非标记探针DNA的混合盐溶液中加入靶标DNA后检测,发现金纳米...     

α-Fe2O3纳米棒的制备及其丙酮气敏性能

在合成原料浓度较高的情况下,利用水热合成的方式制备得到了α-Fe2O3纳米棒,有效提高了水热合成纳米粉末的产量,利用超声处理的方式将团聚的α-Fe2O3纳米棒进行了有效分离,利用X射线衍射(XRD)、傅里叶红外光谱(FTIR)和场发射扫描电镜(SEM)对样品进行了物相分析和形貌观察,测试这种纳米材料在不同温度下对丙酮的气敏性能,通过这种方法制备得到的气敏材料对丙酮具有良好的响应特性,具有工作温度低、检测极限低、选择性和稳定性良好等优势。     

基于微通道的ZnO纳米棒生物荧光检测研究

利用种子法和水热合成技术,分别在常规条件下和阵列式微通道中制备氧化锌(ZnO)纳米棒.采用扫描电子显微镜(SEM)、X射线衍射(XRD)等分析方法表征ZnO纳米棒的表面形貌特点和晶体结构.结果表明:微通道中制备的ZnO纳米棒的比表面积、结晶度和c轴取向性均有较大程度的提高.同时,建立了基于阵列式微通道的ZnO纳米棒生物荧光检测方法,利用ZnO纳米棒可显著增强荧光信号,对异硫氰酸荧光素标记的羊抗牛IgG抗体的检测限为1×10-4 μg/mL.     

氧化锌纳米棒/单晶硅的酒精传感器研究

首先采用射频溅射在单晶硅(Si)上制备氧化锌(ZnO)薄膜,作为生长ZnO纳米棒的晶种层,再在水热条件下生长ZnO纳米棒.X射线衍射、X射线能量色散谱,扫描电镜及室温光致发光谱对样品的物相结构、成分、表面微观形貌和晶体缺陷进行了表征.结果表明合成的ZnO纳米棒是六方纤锌矿结构,长径比较高,结晶良好.研究了ZnO纳米棒/单晶Si传感器在空气和酒精气体中的电压-电流(Ⅰ-Ⅴ)特性,阻抗谱及响应-恢复时间.该传感器在+6 V的偏置电压下,其电阻在0.08 g/L酒精气体中下降71%,响应时间小于1 min,可以作为一种新型的酒精气体传感器.     

SnO_2纳米棒的乙醇气体敏感特性研究

在NaC l+KC l熔盐介质中,在660℃下对利用微乳技术制备的前驱物进行焙烧,成功合成了SnO2纳米棒。利用TEM,XRD对SnO2纳米棒形貌、成分进行了表征和分析,SnO2纳米棒直径为10~20 nm,长度从几百个纳米到几个微米。研究表明:以SnO2纳米棒为原料制备的厚膜气敏元件,对乙醇具有较高的灵敏度、好的选择性和响应-恢复特性。     

金纳米颗粒制备及其光学特性研究

采用晶种生长法通过改变晶种对生长溶液的体积比例、引入离子合成了棒状和星形金纳米颗粒.首先用NaBH4作为还原剂制得小粒径球形金纳米颗粒作为晶种溶液,生长溶液中引入AgNO3为辅助试剂、溴化十六烷三甲基铵(CTAB)为表面活性剂来引导合成形貌不同的颗粒.对制备的球状、棒状和星状金纳米颗粒进行了紫外-可见光谱测试和表面增强...     

Cd2+掺杂SnO2纳米棒的制备与特性研究

在微乳液中SnCl和CdCl的混合水溶液与KBH4水溶液的还原反应制备了Cd2 掺杂SnO2纳米棒前驱物.在NaCl KCl熔盐介质中,660℃焙烧前驱成功制备了Cd2 掺杂SnO2纳米棒一维纳米材料.利用TEM、XRD、XPS和H2-TPR对SnO2纳米棒形貌、成分和材料表面氧吸附特性、H2还原特性进行了表征和分析.SnO2纳米棒直径为10nm～20 nm,长度从几百个纳米到几个微米,Cd2 掺杂后的SnO2纳米棒材料中CdO的含量可达5%.TPR的结果表明,Cd2 掺杂SnO2纳米棒表面吸附大量的氧具有较好的氧化还原特性.以SnO2纳米棒为原料,制备了厚膜气敏元件,考察了其H2敏感特性.     

SnO2纳米棒一维纳米材料气敏特性研究

在NaCl KCl熔盐介质中,在610～760℃焙烧利用室温固相反应合成的SnO2纳米棒前驱物,成功制备了SnO2纳米棒.利用TEM、XRD和XPS对SnO2纳米棒形貌、成分进行了表征和分析,SnO2纳米棒直径为10～60 nm,长度从几百个纳米到十几个微米.以SnO2纳米棒为原料,分别制备了厚膜气敏元件,考察了其气敏特性.在工作温度为300℃左右时,660℃焙烧制备的SnO2纳米棒元件对乙醇具有较高的灵敏度、好的选择性和响应恢复特性.     

金纳米颗粒的绿色制备及其在生物传感器中的应用

由于金纳米颗粒（AuNPs）特殊的化学、物理特性。使其在生物催化及传感器领域有了越来越重要的应用。目前用来制备金纳米材料的方法有很多。近年来采用新型的、洁净无毒的、绿色的方法来合成金纳米粒子越来越受到重视。     

Preparation of ZnO nanorods by microemulsion synthesis and their application as a CO gas sensor

Zinc oxide nanorods with different surface area were synthesized by surfactant assisted microemulsion method. The alkyl chain length of surfactant would affect aspect ratio of ZnO nanorods. ZnO nanorods synthesized by ethyl benzene acid sodium salt (EBS), which is surfactant with short alkyl chain length, show higher aspect ratio than ones by dodecyl benzene sulfonic acid sodium salt (DBS). These nanorods had diameters in the range of 80–300 nm and length of up to several microns. The Brunauer–Emmett–Teller (BET) surface area of the ZnO nanorods was strongly affected by the morphology of the nanorods. The BET surface area of the nanorods synthesized with EBS was higher than the surface area of the nanorods synthesized with DBS (20.2 and 14.1 m²/g for EBS and DBS, respectively). The response of ZnO nanorods to CO in air was strongly affected by surface area, defects and oxygen vacancies. The results demonstrate that the microemulsion synthesis is an easy and useful method to synthesize ZnO nanorods with large aspect ratio, which may enhance their gas sensing properties.     

Sensing of lead ions using glutathione mediated end to end assembled gold nanorod chains

This communication reports the use of glutathione mediated self assembled chains of gold nanorods as new approach for the detection of Pb²⁺ ions. We were prompted to study the influence of metal ions by considering the role of glutathione as detoxification agent in the body. Additionally the ability of glutathione to complex with metal ions like lead (Pb²⁺) and mercury (Hg²⁺) is well known. We studied the interaction of different metal ions including Pb²⁺ with the end to end assembled chains of gold nanorods. Pb²⁺ was found to disassemble the chains to dimeric structures. High resolution transmission electron microscopy and dynamic light scattering were used to study the ensemble. A proportional reduction in the size of the assembly was observed between concentration ranges of 0.1-0.025 mM of Pb²⁺. Our results indicate that analyte induced disassembly is an attractive approach to the detection of environmentally relevant components such as Pb²⁺.     

One-step synthesis and gas sensing characteristics of hierarchical SnO2 nanorods modified by Pd loading

The hierarchical unloaded and Pd-loaded SnO₂ nanostructures, consisting of many aggregative nanorods were prepared by one-step hydrothermal method. A possible formation mechanism of these hierarchical structures was proposed. The butanone sensing properties of the sensors based on unloaded and hierarchical Pd-loaded SnO₂ nanorods were investigated. The results indicate that the response of sensor using hierarchical Pd-loaded SnO₂ nanorods to 1000 ppm butanone was 451 at 250 °C, which was about 10 times higher than that of sensor based on unloaded SnO₂. Such enhanced gas sensing performances can be attributed to both the chemical and the electrical contribution of Pd loading.     

氧化铋掺杂制备SnO2棒状晶粒气敏材料的研究

探讨了氧化铋掺杂的SnO2纳米棒状晶粒气敏材料的制备,并测试了材料的气敏特性。氧化铋在高温形成液相,促进SnO2棒状晶粒的形成,同时氧化铋作为气敏材料的添加剂提高了对乙醇等气体的灵敏度。结果表明,采用液相沉淀法制备纳米粉体,在Bi添加量为10mol%,850℃保温2h的烧结条件下,得到的SnO2棒状晶粒直径约50nm,线径比为5,且较为均一。粉体经过稀硝酸溶液浸泡,其晶粒形貌及相结构不变,酸洗处理后的棒晶粉体制备的气敏元件,电阻值适中,对气体灵敏度提高。对乙醇、丙酮、汽油、苯和氨气的测试说明,氧化铋掺杂的SnO2棒状晶粒作为气敏材料,在不同温区对乙醇和丙酮的灵敏度较高,而且工作温度较低,对汽油、苯和氨气等气体有较好的选择性。     

High-performance liquefied petroleum gas sensing based on nanostructures of zinc oxide and zinc stannate

Toxic and combustible gas detection plays a major role in environmental air quality monitoring. Real-time monitoring of hazardous gases and signal of accidental leakages is of great importance owing to the concern for safety requirements in industries and household applications. A simple and economical method for the fabrication of highly sensitive zinc oxide (ZnO) nanorods based gas sensors for detecting low concentrations of Liquefied Petroleum Gas (LPG) was studied in this work. Platinum (Pt) nanoparticles were deposited on the sensing medium which acts as catalysts to improve the sensor performance. The change in electrical resistance of the metal oxide semiconductor for varying concentrations of LPG was measured. Maximum response of 59% was achieved for 9000 ppm LPG at 250 °C. Further to improve the sensing performance of the sensor towards LPG, surface modification of ZnO nanorods using zinc stannate (Zn₂SnO₄) microcubes was performed. High response of 63% was observed for 3000 ppm LPG at 250 °C. Significant improvement in response of the sensor with Zn₂SnO₄ microcubes on ZnO nanorods was observed when compared to sensor with ZnO nanorods.     

LPG sensing properties of Pd-sensitized vertically aligned ZnO nanorods

One-dimensional (1-D) vertically aligned ZnO nanorods are synthesized on glass substrate through a simple chemical route and their liquefied petroleum gas (LPG) sensing properties are studied. The morphology and structure of vertically aligned ZnO nanorods has been characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The LPG sensing properties of the vertically aligned ZnO nanorods are improved significantly after palladium (Pd) sensitization. The unsensitized vertically aligned ZnO nanorods exhibited the maximum response of 37% at 573 K upon exposure to 2600 ppm LPG, which improved to 60% at operating temperature of 498 K after the Pd sensitization. The Pd-sensitized vertically aligned ZnO nanorods showed more selectivity towards LPG as compared to CO₂. Our results demonstrate that the chemically grown vertically aligned ZnO nanorods along with Pd sensitization are promising material for the fabrication of cost effective and high performance gas sensors.     

Growth of ZnO nanorods on patterned templates for efficient, large-area energy scavengers

ZnO nanostructures were grown on patterned Si substrates using a cost-efficient, low-temperature process, for their future exploitation as functional cores of nanopiezotronic applications. Different substrates and growth parameters were examined in order to determine the optimum process window that will constitute a reliable, low-cost method for large-scale ZnO nanorod production. Statistical analysis was performed to assess the size and shape distribution of the nanorods in an effort to determine the energy conversion efficiency of the resulting structures.     

Synthesis of ZnO nanorods and its application in NO2 sensors

One-dimensional (1D) ZnO nanorods with pencil-like shape and high aspect ratio were successfully synthesized using a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal process at 90 °C. The surface morphology and structure of nanocrystals were characterized by FE-SEM, XRD and XPS analysis. Experimental results show that the surfactant and base concentration play important roles in the formation and growth orientation of ZnO nanorods. The ZnO nanorods synthesized exhibits high response and selectivity to NO₂, the highest response to 40 ppm NO₂ reached 206 and the selectivity with respect to CO and CH₄ at same concentration reached 10.3 and 30 times, respectively. The effects of synthesis method, surfactant and calcination condition on sensing properties were systematically investigated. The results indicate that the CTAB-assisted low temperature hydrothermal process is a potentially facile method for synthesis of 1D ZnO nanorods and excellent potential candidates as gas sensing materials.