细菌视紫红质—稀土上转换纳米粒子生物纳米体系的构建及其红外光电响应研究
发布时间：2019-06-19 02:49
【摘要】：细菌视紫红质(bacteriorhodopsin,bR)是嗜盐菌细胞膜上以碎片形式存在的紫膜(Purple membrane, PM)中的跨膜蛋白。它是一种光敏蛋白,在光照下能通过光循环过程,驱动质子定向移动,并将光能转化为化学能,是一类天然的、易于获取的能量转换器。自1971年被首次发现以来,人们逐渐对其功能特性、结构等进行了广泛而深入的研究。bR的主要功能有：光驱动质子泵功能、光电响应功能、光致变色功能等,其中,伴随光驱动质子移动产生的光电响应功能是研究的热点。到目前为止,由于bR自身的特点,人们对其光电响应方面的研究还集中于用可见光触发, 这既约束了对bR进行研究的光学波长区间范围,又不利于这种潜力巨大的光敏生物材料的发展应用。本文将bR与上转换发光材料(Upconversional nanoparticles, UCNPs)结合在一起,构建了一种红外光触发bR驱动质子泵功能进而产生光电信号的体系,首次将细菌视紫红质光电响应范围拓展到了红外光区,并且对该体系中的光电响应模式作了进一步研究。具体包括以下方面：(1)嗜盐菌(Halobacterial halobium S9)的培养和bR的提取。本研究首先进行了嗜盐菌的接种培养,然后通过收集菌体、酶解、破膜、去除杂质、清洗、蔗糖密度梯度离心等过程获得了bR生物材料。紫外可见吸收光谱、原子力显微镜的表征证实制备的bR可用于后续光电实验研究。依据朗伯比尔定律计算,实验提取的bR浓度为1.65 mg/mL,也可满足后续的实验要求。(2)构建基于bR/UCNPs的光电器件,实现bR的红外光触发光电响应。以水热法合成了聚乙烯亚胺修饰、铒掺杂的钇氟酸钠UCNPs,对该材料的形貌、粒径、晶形、荧光峰位置和发光强度进行了相关表征,证实其可用于后续光电器件的构建。在红外光激发下,UCNPs发射出波长在bR光响应范围内的可见光,从而触发bR产生光电信号。实验中从转化红外光、透过可见光、过滤红外光到检测光电信号等过程,均在一个装置中实现的,因此也提供了一种搭建光电传感器的新思路。(3)制备发射蓝光、绿光的UCNPs,并将其与bR结合,把红外光触发下bR的光电响应信号由瞬时脉冲模式调整为连续方波模式。制备以钇氟酸钠为基质、柠檬酸钠辅助的UCNPs,并通过调整掺杂元素的种类,获得红外光激发下,分别发出蓝光(波长范围450～500nm)和绿光(波长范围520～580nm)的材料。实验证实,该材料具有良好的发光性能,为规则的六棱柱,且晶体结构生长完整、粒径均一。将上述两种UCNPs按照一定比例与bR结合后,构建了纳米复合光电响应器件。在红外光激发下,混合的UCNPs能同时发出蓝光和绿光,其中绿光激发bR进入光循环由基态转化到M态,而蓝光则促进M态回到基态。整个过程伴随发生质子的连续泵出和捕获,在电极附近形成持续、不平衡的质子电化学梯度变化,从而改变了单一波长激发下,bR只能转化光能为瞬态电容电流的模式,获得了红外光照射下持续的光电流信号。该研究首次实现了通过单一红外光源获得bR持续的光电流信号。本研究证明了通过与UCNP的结合将bR的光电响应范围调整到红外光区,并进一步调整其光电响应模式是可行的,这为bR和UCNP提供了新的应用途径。本研究可能会为bR在红外光控生物分子开关、光电转换装置、太阳能电池等方面应用提供新的可能。此外,将bR与pH敏感聚合物结合,还可能实现红外光控药物的靶向释放。
[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.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O657.3
本文编号：2502011
[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.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O657.3
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