【摘要】：細(xì)菌視紫紅質(zhì)(bacteriorhodopsin,bR)是嗜鹽菌細(xì)胞膜上以碎片形式存在的紫膜(Purple membrane, PM)中的跨膜蛋白。它是一種光敏蛋白,在光照下能通過光循環(huán)過程,驅(qū)動(dòng)質(zhì)子定向移動(dòng),并將光能轉(zhuǎn)化為化學(xué)能,是一類天然的、易于獲取的能量轉(zhuǎn)換器。自1971年被首次發(fā)現(xiàn)以來,人們逐漸對(duì)其功能特性、結(jié)構(gòu)等進(jìn)行了廣泛而深入的研究。bR的主要功能有：光驅(qū)動(dòng)質(zhì)子泵功能、光電響應(yīng)功能、光致變色功能等,其中,伴隨光驅(qū)動(dòng)質(zhì)子移動(dòng)產(chǎn)生的光電響應(yīng)功能是研究的熱點(diǎn)。到目前為止,由于bR自身的特點(diǎn),人們對(duì)其光電響應(yīng)方面的研究還集中于用可見光觸發(fā), 這既約束了對(duì)bR進(jìn)行研究的光學(xué)波長(zhǎng)區(qū)間范圍,又不利于這種潛力巨大的光敏生物材料的發(fā)展應(yīng)用。本文將bR與上轉(zhuǎn)換發(fā)光材料(Upconversional nanoparticles, UCNPs)結(jié)合在一起,構(gòu)建了一種紅外光觸發(fā)bR驅(qū)動(dòng)質(zhì)子泵功能進(jìn)而產(chǎn)生光電信號(hào)的體系,首次將細(xì)菌視紫紅質(zhì)光電響應(yīng)范圍拓展到了紅外光區(qū),并且對(duì)該體系中的光電響應(yīng)模式作了進(jìn)一步研究。具體包括以下方面：(1)嗜鹽菌(Halobacterial halobium S9)的培養(yǎng)和bR的提取。本研究首先進(jìn)行了嗜鹽菌的接種培養(yǎng),然后通過收集菌體、酶解、破膜、去除雜質(zhì)、清洗、蔗糖密度梯度離心等過程獲得了bR生物材料。紫外可見吸收光譜、原子力顯微鏡的表征證實(shí)制備的bR可用于后續(xù)光電實(shí)驗(yàn)研究。依據(jù)朗伯比爾定律計(jì)算,實(shí)驗(yàn)提取的bR濃度為1.65 mg/mL,也可滿足后續(xù)的實(shí)驗(yàn)要求。(2)構(gòu)建基于bR/UCNPs的光電器件,實(shí)現(xiàn)bR的紅外光觸發(fā)光電響應(yīng)。以水熱法合成了聚乙烯亞胺修飾、鉺摻雜的釔氟酸鈉UCNPs,對(duì)該材料的形貌、粒徑、晶形、熒光峰位置和發(fā)光強(qiáng)度進(jìn)行了相關(guān)表征,證實(shí)其可用于后續(xù)光電器件的構(gòu)建。在紅外光激發(fā)下,UCNPs發(fā)射出波長(zhǎng)在bR光響應(yīng)范圍內(nèi)的可見光,從而觸發(fā)bR產(chǎn)生光電信號(hào)。實(shí)驗(yàn)中從轉(zhuǎn)化紅外光、透過可見光、過濾紅外光到檢測(cè)光電信號(hào)等過程,均在一個(gè)裝置中實(shí)現(xiàn)的,因此也提供了一種搭建光電傳感器的新思路。(3)制備發(fā)射藍(lán)光、綠光的UCNPs,并將其與bR結(jié)合,把紅外光觸發(fā)下bR的光電響應(yīng)信號(hào)由瞬時(shí)脈沖模式調(diào)整為連續(xù)方波模式。制備以釔氟酸鈉為基質(zhì)、檸檬酸鈉輔助的UCNPs,并通過調(diào)整摻雜元素的種類,獲得紅外光激發(fā)下,分別發(fā)出藍(lán)光(波長(zhǎng)范圍450～500nm)和綠光(波長(zhǎng)范圍520～580nm)的材料。實(shí)驗(yàn)證實(shí),該材料具有良好的發(fā)光性能,為規(guī)則的六棱柱,且晶體結(jié)構(gòu)生長(zhǎng)完整、粒徑均一。將上述兩種UCNPs按照一定比例與bR結(jié)合后,構(gòu)建了納米復(fù)合光電響應(yīng)器件。在紅外光激發(fā)下,混合的UCNPs能同時(shí)發(fā)出藍(lán)光和綠光,其中綠光激發(fā)bR進(jìn)入光循環(huán)由基態(tài)轉(zhuǎn)化到M態(tài),而藍(lán)光則促進(jìn)M態(tài)回到基態(tài)。整個(gè)過程伴隨發(fā)生質(zhì)子的連續(xù)泵出和捕獲,在電極附近形成持續(xù)、不平衡的質(zhì)子電化學(xué)梯度變化,從而改變了單一波長(zhǎng)激發(fā)下,bR只能轉(zhuǎn)化光能為瞬態(tài)電容電流的模式,獲得了紅外光照射下持續(xù)的光電流信號(hào)。該研究首次實(shí)現(xiàn)了通過單一紅外光源獲得bR持續(xù)的光電流信號(hào)。本研究證明了通過與UCNP的結(jié)合將bR的光電響應(yīng)范圍調(diào)整到紅外光區(qū),并進(jìn)一步調(diào)整其光電響應(yīng)模式是可行的,這為bR和UCNP提供了新的應(yīng)用途徑。本研究可能會(huì)為bR在紅外光控生物分子開關(guān)、光電轉(zhuǎn)換裝置、太陽能電池等方面應(yīng)用提供新的可能。此外,將bR與pH敏感聚合物結(jié)合,還可能實(shí)現(xiàn)紅外光控藥物的靶向釋放。
[Abstract]:Bacteriorhodopsin (bR) is a transmembrane protein in the cell membrane of halophilic bacteria in the form of fragments. It is a kind of photosensitive protein, under the light can pass through the light circulation process, drive the proton directional movement, and convert the light energy into chemical energy, it is a kind of natural, easy to obtain energy converter. Since the first discovery in 1971, people have made extensive and in-depth research on their functional characteristics, structures, and so on. The main functions of bR include: light-driven proton pump function, photoelectric response function, photochromic function and so on, in which, the photoelectric response function generated by the light-driven proton movement is the hot spot of the research. So far, because of the characteristics of the bR, the research on the photoelectric response of the bR is also focused on the visible light, which not only constrains the range of the optical wavelength range for the research of the bR, but also is not beneficial to the development and application of the photosensitive biological material with great potential. In this paper, bR is combined with upconversion luminescent materials (UCNPs), an infrared light-triggered bR-driven proton pump function and a system for producing a photoelectric signal are built, And the photoelectric response pattern in the system is further studied. In particular, the following aspects are: (1) the culture of halobacterium halobium S9 and the extraction of bR. In this study, the inoculation and culture of the halophilic bacteria were carried out, and then the bR biological material was obtained by collecting the bacteria, the enzymolysis, the membrane breaking, the removal of the impurities, the washing, the sucrose density gradient centrifugation and the like. The UV-visible absorption spectrum and the characterization of the atomic force microscope confirm that the prepared bR can be used in the subsequent photoelectric experimental study. According to the Lambert's law, the bR concentration is 1.65 mg/ mL, and the subsequent experimental requirements can be met. And (2) constructing a photoelectric device based on the bR/ UCNPs, and realizing the photoelectric response of the infrared light of the bR. The morphology, particle size, crystal form, fluorescence peak position and luminous intensity of the material were characterized by hydrothermal synthesis of polyethyleneimine modified and self-doped sodium bromate UCNPs, and it was proved that it can be used in the construction of subsequent optoelectronic devices. Under the excitation of infrared light, the UCNPs emit visible light with a wavelength in the light response range of the bR, thereby triggering the bR to generate a photoelectric signal. In the experiment, the process of converting infrared light, transmitting visible light, filtering infrared light to detecting photoelectric signal and so on is realized in a device, and a new idea of building a photoelectric sensor is also provided. (3) preparing the UCNPs for emitting blue light and green light, and combining the UCNPs with the bR, and adjusting the photoelectric response signals of the bR under the trigger of the infrared light from the instantaneous pulse mode to the continuous square wave mode. And preparing a material with blue light (wavelength range of 450-500 nm) and green light (wavelength range of 520-580 nm) under the excitation of infrared light by preparing the UCNPs with sodium tetrafluoroborate as a matrix and sodium citrate auxiliary, and by adjusting the kind of the doping elements. The experimental results show that the material has good light-emitting performance, is a regular hexagonal prism, and has a complete crystal structure and uniform grain size. And after the two UCNPs are combined with the bR according to a certain proportion, the nano composite photoelectric response device is constructed. Under the excitation of infrared light, the mixed UCNPs can emit blue light and green light at the same time, wherein the green light excites the bR to enter the light circulation from the ground state to the M state, and the blue light promotes the M state to return to the ground state. the whole process is accompanied by continuous pumping and capture of protons, and the continuous and unbalanced proton electrochemical gradient changes are formed in the vicinity of the electrodes, so that under the excitation of a single wavelength, the bR can only convert the light energy into a transient capacitance current mode, And the continuous photocurrent signal under the irradiation of the infrared light is obtained. This study first achieved the acquisition of a bR continuous photocurrent signal through a single infrared source. This study has shown that the photoelectric response range of bR is adjusted to the infrared region by the combination with the UCNP, and the photoelectric response mode of the BR is further adjusted to be feasible, which provides a new application approach for bR and UCNP. This study may provide new possibilities for the application of bR in infrared-controlled bio-molecular switches, photoelectric conversion devices, solar cells, and the like. In addition, the binding of the bR to the pH-sensitive polymer and the targeted release of the infrared light-controlled drug may also be achieved.
【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.1;O657.3

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前2條

1 吳佳;視黃醛膜蛋白的質(zhì)子泵功能及其光響應(yīng)器件材料的研究[D];復(fù)旦大學(xué);2009年

2 夏露;靶向上轉(zhuǎn)換納米光敏劑構(gòu)建及其醫(yī)學(xué)應(yīng)用研究[D];中國科學(xué)院研究生院(長(zhǎng)春光學(xué)精密機(jī)械與物理研究所);2014年

相關(guān)碩士學(xué)位論文 前2條

1 李冬冬;用嗜鹽菌制備視紫紅質(zhì)和分離檢測(cè)不飽和脂肪酸[D];北京化工大學(xué);2007年

2 張強(qiáng);稀土離子摻雜的NaYF4納米材料的水熱合成與光譜表征[D];復(fù)旦大學(xué);2008年

，

本文編號(hào)：2502011