本文選題：石墨烯　切入點(diǎn)：斜生柵藻　出處：《浙江工商大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：石墨烯作為一種新興的二維碳納米顆粒,因其優(yōu)良的性能在能源存儲(chǔ)、納米電子設(shè)備、電池、透明導(dǎo)體和環(huán)境保護(hù)等方面有著廣泛應(yīng)用。隨著石墨烯材料的大量使用,它們最終可能被釋放到水、陸地和大氣環(huán)境中。然而,石墨烯的生態(tài)風(fēng)險(xiǎn)和毒性機(jī)制目前尚未明確。本文以石墨烯作為研究對(duì)象,探究其對(duì)斜生柵藻(Scenedesmus obliquus)和小麥(Triticum aestivum L.)的毒性效應(yīng)及內(nèi)在機(jī)制,以期為今后石墨烯的生態(tài)效應(yīng)研究提供理論依據(jù)。主要內(nèi)容包括以下幾部分：(1)不同石墨烯濃度0、10、20、50、100、150、200、250和300 mg L-1對(duì)斜生柵藻的生長(zhǎng)影響表明,72 h后石墨烯能顯著抑制斜生柵藻的生長(zhǎng),抑制現(xiàn)象呈濃度、時(shí)間效應(yīng)。經(jīng)Logistic和Gompertz模型計(jì)算ICso值分別為148和151 mg L-1。掃描和透射電鏡分析石墨烯對(duì)藻細(xì)胞胞外和胞內(nèi)顯微形態(tài)影響結(jié)果表明,150 mg L-1石墨烯處理下藻細(xì)胞表面包裹一層薄膜；與對(duì)照相比,石墨烯處理后藻細(xì)胞的細(xì)胞壁呈破損現(xiàn)象；胞內(nèi)兩個(gè)明顯的生理變化為染色質(zhì)高度濃縮及細(xì)胞內(nèi)淀粉粒增多。上述現(xiàn)象表明,石墨烯引起的胞外覆蓋和胞內(nèi)損傷可能是影響藻細(xì)胞生長(zhǎng)的重要原因。此外,本研究還發(fā)現(xiàn)藻細(xì)胞的細(xì)胞膜通透性隨石墨烯濃度升高而增大,表明藻細(xì)胞膜的完整性遭到破壞。通過(guò)測(cè)定藻細(xì)胞體內(nèi)活性氧自由基(ROS)和丙二醛(MDA)含量發(fā)現(xiàn),它們均隨石墨烯濃度的升高而增加,說(shuō)明藻細(xì)胞受到顯著的氧化脅迫。另外,石墨烯還顯著抑制了葉綠素a、葉綠素b及葉綠素a/b水平,暗示著光合作用受損。葉綠素?zé)晒飧鲄?shù)分析結(jié)果表明,石墨烯處理后藻細(xì)胞光合系統(tǒng)Ⅱ(PSⅡ)實(shí)際量子產(chǎn)量Y(Ⅱ)、光化學(xué)淬滅系數(shù)qP、非光化學(xué)淬滅系數(shù)NPQ和相對(duì)光合電子傳遞速率rERT與對(duì)照組相比均降低,說(shuō)明PSⅡ活性受損。由此,本研究認(rèn)為石墨烯對(duì)藻細(xì)胞的毒性效應(yīng)主要表現(xiàn)為胞外表面覆蓋和胞內(nèi)氧化損傷、光合作用受損,最終影響藻細(xì)胞的生長(zhǎng)。(2)48 h短期石墨烯處理下小麥根系生長(zhǎng)結(jié)果表明,250、500、1000和1500 mg L-1石墨烯處理與對(duì)照相比根系伸長(zhǎng)率分別增加了69%、221%、208%和288%,說(shuō)明石墨烯對(duì)小麥根系的生長(zhǎng)有一定的促進(jìn)。顯微觀察發(fā)現(xiàn)這可能與處理后細(xì)胞拉伸有關(guān)。此外,石墨烯處理下小麥根系出現(xiàn)了以下變化：根毛短而稀疏；根內(nèi)MDA含量高；硝基四唑氮藍(lán)和伊文思藍(lán)染色增強(qiáng)；超氧化物歧化酶(SOD)和過(guò)氧化物酶(POD)活性隨石墨烯濃度的升高先激活后抑制。上述現(xiàn)象均說(shuō)明石墨烯處理后根系抗氧化系統(tǒng)受損。因此,石墨烯對(duì)小麥的短期毒性效應(yīng)主要表現(xiàn)為根系的氧化脅迫及根毛發(fā)育遲緩。(3)30 d石墨烯處理下小麥生長(zhǎng)結(jié)果表明,500 mg L-1石墨烯處理中小麥地上部生物量顯著下降,葉片葉綠素含量降低,說(shuō)明石墨烯長(zhǎng)期處理可抑制小麥的生長(zhǎng)。為研究石墨烯對(duì)小麥體內(nèi)養(yǎng)分含量的影響,本研究首先分析了大量元素氮、磷和鉀的情況。結(jié)果表明,石墨烯處理后葉片總氮、總鉀含量下降,總磷含量基本保持不變。此外,石墨烯處理后葉片的中量元素如鈣和鎂含量也呈下降現(xiàn)象,而鈉含量基本保持不變。石墨烯處理中小麥葉片的微量元素如鋅、鐵和銅含量降低,錳含量升高。上述數(shù)據(jù)說(shuō)明,石墨烯長(zhǎng)期處理后小麥體內(nèi)大部分養(yǎng)分均受到了一定程度的抑制。因此,石墨烯對(duì)植物的養(yǎng)分代謝影響也是其毒性效應(yīng)的重要表征。
[Abstract]:Graphene as a new two-dimensional carbon nano particles, because of its excellent performance in energy storage, nano electronic devices, batteries, have been widely applied in transparent conductors and environmental protection. With the extensive use of graphene materials, they may eventually be released into the water, land and air. However, graphite by the ecological risk and toxicity mechanism is not yet clear. This paper takes Shi Moxi as the research object, research on Scenedesmus (Scenedesmus obliquus) and wheat (Triticum aestivum L.) the toxic effects and mechanism, so as to provide theoretical basis for future research on the ecological effects of graphene. The main contents include the following parts: (1) showed that the effect of different concentrations of 0,10,20,50100150200250 graphene and 300 mg L-1 on the growth of Scenedesmus, after 72 h of graphene can significantly inhibit the growth of Scenedesmus obliquus, inhibit the phenomenon of dark Of the time effect. The results of Logistic and Gompertz model to calculate the ICso values were 148 and 151 mg L-1. scanning electron microscope and transmission electron microscope analysis results the morphology of graphene on cell extracellular and intracellular showed that 150 mg L-1 graphene under the treatment of the algal cell surface covered with a layer of thin film; compared with the control group, after treatment of graphene the cell wall of algal cells were damaged; two obvious physiological changes in intracellular for highly condensed chromatin and starch in cells increased. The phenomenon shows that the influence of growth of algae is an important reason why graphene may damage caused by extracellular and intracellular coverage. In addition, the study also found that the permeability of cell membrane algal cells increased with the concentration of graphene increases, integrity that algae cell membrane destruction. Through the determination of algal cells in vivo activity of oxygen free radicals (ROS) and malondialdehyde (MDA) content, they are with the concentration of graphene The increase that algal cells by oxidative stress significantly. In addition, graphene also inhibited the chlorophyll a, chlorophyll b and chlorophyll a/b levels, suggesting that photosynthesis is damaged. The parameters of chlorophyll fluorescence analysis results show that the graphene processed algal photosynthetic system II (PS II) the actual quantum yield (Y II), photochemical quenching coefficient qP, non photochemical quenching coefficient NPQ and the relative photosynthetic electron transport rate of rERT was lower compared with control group, indicating the damage of PS II activity. Thus, this study suggests that the toxic effect of graphene on cell mainly oxidative damage, extracellular and intracellular photosynthesis damaged surface coverage finally, affect the growth of algal cells. (2) 48 h short graphene under the treatment of root growth of wheat. The results showed that 2505001000 mg and 1500 L-1 graphene on photographic processing and root elongation were increased by 69%, 221%, 208% And 288%, that the growth of graphene on wheat root has certain promotion. This may be associated with the microscopic observation results showed that the cells treated with tension. In addition, graphene treatment appeared the following changes: wheat root hairs short and sparse; the content of MDA in the roots; four nitro tetrazolium and Evans blue staining enhancement; superoxide dismutase (SOD) and peroxidase (POD) activity increased with the concentration of graphene activation inhibition. This phenomenon showed impaired antioxidant system root of graphene after treatment. Therefore, the short-term toxicity of Shi Moxi wheat mainly manifested as root oxidative stress and root hair growth retardation (3) 30. D graphene under the treatment of wheat growth. The results showed that 500 mg L-1 graphene processing biomass and wheat decreased significantly, chlorophyll content decreased, indicating graphene long-term treatment could inhibit the growth of wheat for research. The effect of graphene on nutrient content in wheat, this study first analyzed the nitrogen, phosphorus and potassium. The results show that the graphene processed leaf total nitrogen, total potassium content decreased, total phosphorus content remained unchanged. In addition, graphene treated leaf elements such as calcium and magnesium content in a declining phenomenon, and the sodium content remained unchanged. The graphene processing of wheat leaf trace elements such as zinc, iron and copper content decreased, manganese content increased. The above data shows that graphene long-term treatment most of the nutrient in wheat was inhibited to a certain extent. Therefore, the important effect of characterization of graphene nutrient metabolism the plant is also its toxic effects.

【學(xué)位授予單位】：浙江工商大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X171.5;TQ127.11

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 崔o，

本文編號(hào)：1621147