本文選題：鈾　切入點(diǎn)：DNA酶　出處：《南華大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：鈾作為核工業(yè)發(fā)展的主要原材料,在利用過(guò)程中會(huì)帶來(lái)放射性核素污染問(wèn)題,由此帶來(lái)的危害主要表現(xiàn)在兩個(gè)方面:化學(xué)毒性和輻射毒性�；瘜W(xué)毒性表現(xiàn)在對(duì)腎臟、免疫系統(tǒng)、神經(jīng)系統(tǒng)、生殖生育等影響,輻射毒性則是DNA致突和致癌作用。鈾的現(xiàn)行檢測(cè)方法中,存在檢測(cè)儀器昂貴,或是檢測(cè)限高、干擾較大等問(wèn)題。所以,建立簡(jiǎn)便、選擇性好、靈敏度高的檢測(cè)方法對(duì)于環(huán)境中鈾污染物的有效監(jiān)測(cè)、防患于未然是極其重要的。本文第二章建立了核酸外切酶III輔助底物碎片循環(huán)信號(hào)放大超靈敏檢測(cè)鈾酰離子的新方法。鈾酰離子能特異性地與DNA酶作用,誘導(dǎo)DNA酶的構(gòu)象發(fā)生變化,釋放出ss DNA。加入MB之后,游離出的ss DNA與分子信標(biāo)雜交形成雙鏈,加入ExoⅢ后,外切酶Ⅲ對(duì)特定識(shí)別位點(diǎn)進(jìn)行剪切,打開(kāi)的MB被剪切為單個(gè)堿基,而ss DNA不被剪切并與下一個(gè)MB雜交,引起二次循環(huán)裂解,導(dǎo)致熒光信號(hào)積聚,經(jīng)過(guò)多次循環(huán),可使熒光信號(hào)放大。在優(yōu)化出的最佳實(shí)驗(yàn)條件下,鈾酰離子濃度范圍為8.1×10-12mol/L~9.5×10-11mol/L時(shí),體系的熒光變化值呈現(xiàn)較好的線性關(guān)系,線性回歸方程為ΔF=162.3c(10-11mol/L)+22.01,相關(guān)系數(shù)r=0.990。根據(jù)空白管的標(biāo)準(zhǔn)偏差Sb和標(biāo)準(zhǔn)曲線的斜率k算出LOD為2.4p M。該方法選擇性好,靈敏度高于迄今為止已報(bào)道的方法。本文第三章建立了非標(biāo)記DNAzyme構(gòu)象改變熒光法檢測(cè)鈾酰離子的新方法。實(shí)驗(yàn)表明,在p H 5.5 MES緩沖溶液中,當(dāng)體系中不存在鈾酰離子時(shí),SYBR GreenⅠ(SG)能通過(guò)嵌入和小溝結(jié)合方式與脫氧核酶作用,導(dǎo)致熒光增強(qiáng);當(dāng)鈾酰離子存在時(shí),DNAzyme的r A堿基處斷裂,游離出單鏈,此時(shí)SG與單鏈DNA作用減弱,熒光信號(hào)降低,且體系的熒光強(qiáng)度變化值與鈾酰離子濃度在1.73×10 9~4.40×10 8 mol/L范圍內(nèi)呈良好線性關(guān)系,線性回歸方程為ΔF=108.99c(×10-8mol/L)+79.22,相關(guān)系數(shù)r=0.990。根據(jù)空白管的標(biāo)準(zhǔn)偏差Sb和標(biāo)準(zhǔn)曲線的斜率k算出LOD為5.2×10 10 mol/L。該方法操作簡(jiǎn)單、選擇性好,靈敏度高。本文第四章基于DNAzyme-MB-GO系統(tǒng),提出了檢測(cè)鈾酰離子的生物傳感策略。研究表明,鈾酰離子能特異性地與DNAzyme作用,誘導(dǎo)DNA酶的構(gòu)象發(fā)生變化,釋放出單鏈DNA(ss DNA),加入單標(biāo)記的分子信標(biāo)(MB),游離出的ss DNA與MB雜交形成雙鏈,隨后加入氧化石墨烯(GO),此時(shí)未被雜交的分子信標(biāo)將會(huì)被氧化石墨烯吸附,導(dǎo)致熒光背景信號(hào)降低。鈾酰離子濃度范圍為1.35×10 9~2.5×10 8 mol/L和1.03×10 8~1.75×10 7 mol/L時(shí),體系的熒光變化值呈現(xiàn)較好的線性關(guān)系,線性回歸方程分別為ΔF=20.19c(×10-8 mol/L)+0.13和ΔF=26.59c(×10-7mol/L)+57.36;相關(guān)系數(shù)分別為r=0.980和r=0.993。根據(jù)空白管的標(biāo)準(zhǔn)偏差Sb和標(biāo)準(zhǔn)曲線的斜率k算出LOD為4.06×10 10mol/L。
[Abstract]:Uranium, as the main raw material for the development of the nuclear industry, will bring about the problem of radionuclide contamination in the process of utilization. The harm caused by it is mainly manifested in two aspects: chemical toxicity and radiation toxicity. Chemical toxicity is manifested in the kidney and immune system. The effects of nervous system, reproduction and fertility, radiation toxicity are caused by DNA and carcinogenicity. Among the current methods for the detection of uranium, there are some problems, such as expensive detection instruments, high detection limits, large interference, etc. Therefore, it is easy to establish, good selectivity, and so on. Highly sensitive methods for the effective monitoring of uranium contaminants in the environment, In the second chapter, a new method for the detection of uranyl ion by amplification of cyclic signal of nucleic acid exonuclease (III) assisted substrate fragment is established. Uranyl ion can specifically interact with DNA enzyme. The conformation of DNA was induced to change, and ss DNA was released. After adding MB, the free ss DNA was hybridized with molecular beacon to form double strands. After adding Exo 鈪，

本文編號(hào)：1622540