DNA保护银纳米团簇的合成及其光电致发光性质的研究

中文摘要以含不同数量胞嘧啶(C)碱基茎−环结构(stem-loop hairpin)序列特定的单链寡聚核苷酸(ssDNA)、硼氢化钠(NaBH4)、硝酸银(AgNO3)和乙酸铵([CH3COO−][NH4+])为原料合成了ssDNA保护的银纳米团簇(Ag nanoclusters，简称AgNCs，AgNCs@DNA)，对AgNCs@DNA进行了紫外−可见吸收光谱、光致发光(荧光)光谱(PL)及电致发光光谱(ECL)等光谱表征和测量。结果证明了AgNCs@DNA的荧光光谱有两个发射峰，且发射峰位置随着DNA序列中C碱基的个数与静置时间而改变，发光强度也会变化，但是电致发光现象不明显。继而探讨了AgNCs@DNA对CdS量子点(CdS QDs)的激子态发光行为的影响，结果显示加入AgNCs@DNA后，CdS QDs的PL和ECL强度都有大幅下降，证实了AgNCs@DNA对CdS QDs的高效的猝灭效应。63857

关键词DNA；银纳米团簇；量子点；荧光；电致发光；猝灭

Abstract Deoxyribonucleic acid-protected silver nanoclusters (AgNCs@DNA) was successfully synthesized with single-stranded hairpin oligo-nucleotide (ssDNA) containing a cytosine (C)-rich loop, sodium borohydride (NaBH4), silver nitrate (AgNO3) and ammonium acetate ([CH3COO−][NH4+]). The optical properties of as-prepared AgNCs@DNA were characterized and analyzed by UV-Vis absorption, photoluminescence (PL) and electrochemiluminescence (ECL) spectra. The PL spectrum of AgNCs@DNA showed two emission peaks whose positions as well as intensities varied with the amount of C bases and storing duration. However, the ECL behavior of AgNCs@DNA was unwitnessed. The influences of AgNCs@DNA on the excitonic luminescent behavior of CdS QDs were further investigated. Great decline in both PL and ECL intensities of CdS QDs aqueous solution were observed after AgNCs@DNA was introduced into, demonstrating a highly PL plus ECL quenching efficiency of AgNCs@DNA upon CdS QDs.

Keywords DNA; Silver nanocluster; Quantum dot; Photoluminescence; Electrochemiluminescence; Quenching

中文摘要 03

Abstract 04

第一章绪论 05

1.1纳米团簇简介 05

1.2 DNA纳米技术 06

1.3光致发光 08

1.4电致发光 08

1.5猝灭效应 09

第二章 DNA保护银纳米团簇的合成及其光/电致发光性质的研究 11

2.1实验材料 11

2.1.1实验试剂 11

2.1.2实验仪器和设备 11

2.2实验方法和步骤 11

2.2.1 AgNCs@DNA的合成 11

2.2.2 AgNCs@DNA的光谱表征 12

2.2.3 AgNCs@DNA的ECL行为 13

2.2.4 AgNCs@DNA对CdS QDs的猝灭效应 14

2.2.5注意事项 15

2.3实验结果和分析讨论 15

2.3.1 AgNCs@DNA和CdS QDs的紫外光谱图 15

2.3.2 AgNCs@DNA的荧光光谱图 16

2.3.3 AgNCs@DNA的ECL光谱图 18

2.3.4 AgNCs@DNA对CdS QDs的猝灭效应 18

2.4结论 21

致谢 22

参考文献 23 第一章绪论

1.1纳米团簇简介 DNA保护银纳米团簇的合成及其光电致发光性质的研究:http://www.751com.cn/huaxue/lunwen_70660.html