本文選題：量子點 + 半胱氨酸��； 參考：《東北大學(xué)》2008年碩士論文

【摘要】：量子點以其優(yōu)越的光學(xué)性能,迅速成為人們關(guān)注的熱點。與傳統(tǒng)的有機(jī)熒光染料相比,量子點的激發(fā)光譜寬而連續(xù)、發(fā)射光譜窄且對稱、發(fā)射波長可以通過控制粒徑大小和組成來調(diào)諧。量子點的熒光強(qiáng)度及穩(wěn)定性是普通熒光染料的1-2個數(shù)量級,并且生物兼容性好,有望成為熒光探針的首選。本論文采用L-半胱氨酸修飾的CdTe量子點作為熒光探針,研究了水溶性量子點與蛋白質(zhì)的鏈接,與重金屬離子的選擇性響應(yīng),以及生物應(yīng)用和化學(xué)分析等。具體內(nèi)容如下： 以半胱氨酸修飾的CdTe量子點作為生物探針,建立了一種定量測定人血清白蛋白的新方法。量子點表面的羧基經(jīng)活化后與蛋白質(zhì)上的氨基進(jìn)行共價偶聯(lián),可以使量子點的熒光強(qiáng)度得到有效地增強(qiáng)。通過對反應(yīng)條件的優(yōu)化,得出在最佳實驗條件下,人血清白蛋白在4.0×10-4-8.5 mg/L的濃度范圍內(nèi)與熒光強(qiáng)度呈現(xiàn)良好的線性關(guān)系,線性相關(guān)系數(shù)為0.9994,方法的檢出限可達(dá)0.13μg/L(3σ),相對標(biāo)準(zhǔn)偏差為0.5%(4.0mg/L,n=11)。將該方法用于人血清中總蛋白含量的測定,結(jié)果與考馬斯亮藍(lán)G-250測定蛋白質(zhì)含量的經(jīng)典方法得到的結(jié)果一致。F檢驗和t檢驗的結(jié)果表明兩種分析方法無顯著性差異。 根據(jù)半胱氨酸修飾的CdTe量子點對汞離子的選擇性響應(yīng),建立了一種量子點作為離子探針定量檢測痕量Hg2+的新方法。在最佳實驗條件下,量子點熒光強(qiáng)度的變化與Hg2+濃度呈良好的線性關(guān)系,線性范圍是0.24-15.0μg/L,方法的檢出限為0.07μg/L(3σ),對濃度為7.38μg/L的汞標(biāo)準(zhǔn)溶液平行測定11次,得到的相對標(biāo)準(zhǔn)偏差為0.84%。此外,對反應(yīng)機(jī)理進(jìn)行了探討,認(rèn)為汞的加入使CdTe的表面包覆了一層帶隙更小的Hg(OH)2,導(dǎo)致體系的熒光淬滅。該方法已成功應(yīng)用于自來水中汞離子的測定。
[Abstract]:Quantum dots (QDs) have become the focus of attention for their superior optical properties. Compared with traditional organic fluorescent dyes, the excitation spectrum of quantum dots is wide and continuous, the emission spectrum is narrow and symmetrical, and the emission wavelength can be tuned by controlling the particle size and composition. The fluorescence intensity and stability of quantum dots are 1-2 orders of magnitude of ordinary fluorescent dyes, and their biological compatibility is good, which is expected to be the first choice of fluorescent probes. In this paper, CdTe quantum dots modified with L-cysteine were used as fluorescence probes to study the links between water-soluble QDs and proteins, their selective responses to heavy metal ions, biological applications and chemical analysis. The details are as follows: A new method for quantitative determination of human serum albumin (HSA) was established using cysteine modified CdTe quantum dots as biological probe. The fluorescence intensity of quantum dots can be effectively enhanced by covalent coupling of carboxyl groups on the surface of quantum dots with amino groups on protein. By optimizing the reaction conditions, a good linear relationship between the fluorescence intensity and the concentration of human serum albumin in the concentration range of 4.0 脳 10-4-8.5 mg/L was obtained. The linear correlation coefficient was 0.9994, the detection limit of the method was 0.13 渭 g/L(3 蟽 ~ (-1) and the relative standard deviation was 0.50 mg 路L ~ (-1) 路L ~ (11). The method was applied to the determination of total protein content in human serum. The results were in agreement with those obtained by Coomassie brilliant blue G-250 and t-test. There was no significant difference between the two methods. Based on the selective response of cysteine modified CdTe quantum dots to mercury ions, a new method for quantitative determination of trace Hg2 using quantum dots as ion probes has been developed. Under the optimum experimental conditions, the fluorescence intensity of quantum dots has a good linear relationship with the concentration of Hg2. The linear range is 0.24-15.0 渭 g / L, the detection limit of the method is 0.07 渭 g/L(3 蟽 ~ (-1), and the relative standard deviation is 0.84 for the mercury standard solution of 7.38 渭 g 路L ~ (-1) 路L ~ (-1). In addition, the reaction mechanism is discussed. It is considered that the addition of mercury makes the surface of CdTe coated with a layer with smaller band gap, which leads to fluorescence quenching of the system. The method has been successfully applied to the determination of mercury ions in tap water.
【學(xué)位授予單位】：東北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2008
【分類號】：R341

【引證文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 秦利霞;納米界面仿生功能化及其在生命分析中的應(yīng)用研究[D];華東理工大學(xué);2012年

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本文編號：1856056