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光电化学传感是近年来兴起并发展迅速的一种生物分析技术,其检测的主要原理是生物识别原件识别靶标物质而引起光电活性材料的光电性能变化,最终导致光电流值发生变化,从而达到检测的目的。由于光电化学生物分析中输入信号是光,输出信号是电,这赋予了此种检测方法背景信号低、灵敏度高的天然优势,这种优势所展现出来的潜力使光电化学分析在检测领域受到了越来越多的关注。本文介绍了光电化学生物传感的基本原理、光电活性材料的分类以及光电化学生物传感的传感模式,最后对其未来的发展进行了展望。 相似文献
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神经化学信号传递是实现大脑复杂功能的基础,因此发展神经化学信号的活体原位检测方法,对于探索脑功能和脑疾病的神经化学分子机制具有重要意义。光电化学传感技术具有灵敏度高、背景信号低和易于微型化等优点,是活体原位分析的潜在有力工具。然而,常见的光电活性材料需要短波长的光激发,其组织穿透深度不足,限制了在活体分析中的应用。基于此,本文构建了一种可近红外激发的光电化学微传感器,用于脑内三磷酸腺苷(ATP)的原位检测。将稀土掺杂的上转换纳米颗粒(UCNPs)引入传感界面,用UCNPs的发光激发电极表面的光电活体材料产生光电流信号,通过荧光染料(TAMRA)标记的核酸适配体调节UCNPs的发光,发展一种基于光学调控策略检测脑内ATP的光电化学传感新方法。所制备的微传感器成功用于炎症模型中小鼠脑内ATP的原位检测,初步探索了脑部炎症与ATP水平变化的关系。 相似文献
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光电化学传感器以光作为激发源,以光电流或光电压作为检测信号,具有响应快速、灵敏度高、设备简单等特点,目前已在环境、食品、医学等多个领域的分析测试中得到广泛应用。该文阐述了光电转换材料与光电化学传感器的制备方法,介绍了光电化学传感器的原理和分类。光电化学传感器包含光寻址电位型传感器和电流型光电化学传感器,其中,电流型光电化学传感器由于优良的光电性能、检出限低、所需材料低廉且易加工等优势而被广泛应用。文中着重介绍了电流型光电化学传感器在金属离子、有机污染物、核酸、蛋白质、细胞等方面的应用,并对光电化学传感器的发展前景进行了展望。 相似文献
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近年来,光电化学传感器的研究已经成为人们关注的热点。光敏材料作为光电化学传感器的关键部分,其性能对传感器的灵敏度、选择性和稳定性等特征起着决定性的作用。该文简要介绍了光电化学传感器的原理和光电材料的分类,阐述了在光电化学传感器中常见过渡金属氧化物及其复合物的光电材料的制备方法与应用,对光电化学传感器及光电化学材料的发展前景进行了展望(引用文献67篇)。 相似文献
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光电化学传感器是以光为激发源,光电流或光电压为检测信号,通过电化学、生物识别等手段定量分析待测物与光电流或光电压之间关系的新型技术。其原理是当光照射到光电活性材料时,材料中的电子受到激发,其上面的识别探针捕获目标分析物,引起光电流或光电压变化。当目标物的浓度变化时,光电信号发生相应的变化,两者之间呈现出函数关系,因此,可以通过光电信号变化,来定量测定目标物。在光电化学传感器中,因其激发源(光)与检测信号(电流或电压)的完全分离极大地减少了背景信号的干扰;又因具有响应快速、灵敏度高、设备简单、价格低廉易于微型化等优点,使光电化学传感器在各大领域备受瞩目。本文介绍了光电化学传感器的基本原理、特点、分类及其应用,并对有代表性的研究和发展前景做了总结和评述。 相似文献
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We have developed a photochemical cell using a combination of photosynthetic electron transport (photosystem I particles)
and the photoreduction of a dye such as flavin mononucleotide (FMN) (6). The overall power conversion efficiency depends on the rate of charge transfer across the electrode surfaces in addition
to the efficiency of the photosynthetic and photochemical reactions. For this reason, we studied the effect of varying the
nature of the electrodes on the power developed. We found that reticulated vitreous carbon electrodes showed higher power
conversion efficiencies than did nickel mesh, platinum, or SnO2 glass. There are two reasons for this. First, the ratio of actual to apparent surface area is greater for RVC electrodes
than for the others. Second, FMN and its photoproducts react better with carbon than platinum electrodes. Substituting RVC
electrodes for platinum increased the power conversion efficiency from 1.0 to 3.9%. Platinizing platinum, nickel mesh, or
brass electrodes also increased the power developed. However, the photopotential remained stable for several hours only for
the platinized platinum electrodes. 相似文献
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A photoinduced proton reduction to produce H2 was found to take place in the system using zinc tetraphenylporphine (ZnTPP) incorporated into a Nafion® membrane coated on a platinum electrode (denoted as Pt/Nf[ZnTPP]). When visible light (λ > 390 nm) was irradiated on the Pt/Nf[ZnTPP] system, a photocurrent was generated under applied potentials below −0.10 (v. Ag/AgCl). The action spectrum for the photocurrent agreed with the absorption spectrum of the Nf[ZnTPP] membrane, showing that the present photochemical process is induced on light absorption by the ZnTPP. By measuring the emission decay of ZnTPP under the photoelectrochemical conditions, it was exhibited that the emission from the singlet excited ZnTPP is quenched by the cathodic potentials. The amount of the H2 produced increased with the cathodic potentials. These results indicated that, in the photochemical primary process, a reductive quenching takes place by electron injection from the Pt electrode to the singlet excited ZnTPP forming ZnTPP.–, subsequently leading to the H2 formation by a bimolecular catalysis of the ZnTPP. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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Michael Volokh Guiming Peng Jesús Barrio Menny Shalom 《Angewandte Chemie (International ed. in English)》2019,58(19):6138-6151
Graphitic carbon nitride materials (CNs) have emerged as suitable photocatalysts and heterogeneous catalysts for various reactions thanks to their tunable band gap, suitable energy‐band position, high stability under harsh chemical conditions, and low cost. However, the utilization of CN in photoelectrochemical (PEC) and photoelectronic devices is still at an early stage owing to the difficulties in depositing high‐quality and homogenous CN layer on substrates, its wide band gap, poor charge‐separation efficiency, and low electronic conductivity. In this Minireview, we discuss the synthetic pathways for the preparation of various structures of CN on substrates and their underlying photophysical properties and current photoelectrochemical performance. The main challenges for CN incorporation into PEC cell are described, together with possible routes to overcome the standing limitations toward the integration of CN materials in PEC and other photoelectronic devices. 相似文献
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植物光合作用在其叶绿体的光合作用膜上进行。它有两个串联着的光系统(PSII和PSI)。PSII在膜的一侧,吸收波长相当于680nm的光子激发电子并产生空穴,空穴将水氧化得氧。电子经过一系列的下坡传送,暗反应合成ATP,到处于膜另一侧的PSI。PSI吸收波长相当于700nm的光子,再次将电子激发,经过第二个系列的下坡传送,暗反应将NADP还原为NADHP。NADHP和ATP最终将CO2还原为碳水化合物。 相似文献
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A new photoelectrochemical method for the determination of glucose based on the photoelectrochemical effect of poly(thionine) photoelectrode to hydrogen peroxide (H2O2) was reported. The H2O2‐sensitive photoelectrode was fabricated by electropolymerizing thionine on the surface of ITO electrode. And then glucose oxidase was immobilized on the photoelectrode via the aid of chitosan enwrapping, forming an enzyme‐modified photoelectrode. The photoelectrode was employed as an electron acceptor; H2O2 from the catalytic reaction of enzyme was employed as an electron donor, developing an analytical method of glucose without hydrogen peroxidase. In the paper, the photoelectrochemical effects of photoelectrode to H2O2 and glucose were studied. The effects of the bias voltage and the electrolyte pH on the photocurrent were investigated. The linear response of glucose concentrations ranged from 0.05 to 2.00 mmol/L was obtained with a detection limit of 22.0 µmol/L and sensitivity of 73.2 nA/(mmol·L?1). The applied feasibility of method was acknowledged through monitoring the glucose in practical samples. 相似文献
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Photoelectrochemical(PEC)water splitting is an effective strategy to convert solar energy into clean and renewable hydrogen energy.In order to carry out effective PEC conversion,researchers have conducted a lot of exploration and developed a variety of semiconductors suitable for PEC water splitting.Among them,metal oxides stand out due to their higher stability.Compared with traditional oxide semiconductors,ferrite-based photoelectrodes have the advantages of low cost,small band gap,and good stability.Interestingly,due to the unique characteristics of ferrite,most of them have various tunable features,which will be more conducive to the development of efficient PEC electrode.However,this complex metal oxide is also troubled by severe charge recombination and low carrier transport efficiency,resulting in lower conversion efficiency compared to theoretical value.Based on this,this article reviews the structure,preparation methods,characteristics and modification strategies of various common ferrites.In addition,we analyzed the future research direction of ferrite for PEC water splitting,and looked forward to the development of more efficient catalysts. 相似文献
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HAN Yun-Yu ZHOU Wu LU Shao-Fen ZHOU Rui-LingDepartment of Chemistry Shandong Teachers University Jinan Shandong S China 《中国化学》1996,14(2):147-151
A photosensitive electrode was prepared by electrodepositing a membrane of chlorophyll a (Chla) on a SnO2 optical transparent electrode,with which and a metal counter electrode a Chla photoelectrochemical cell was formed.Photoinduced current (Ii) and photoinduced voltage (Vi) of the cell were measured.The dependence of Ii on the properties of metal electrodes was obvious,which was illustrated with mechanism of Chla photoelectrical effects Ii in this work was as high as 2×10-5 A·cm-2. 相似文献
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In this article, we describe a solid-state photoelectrochemical cell for light detection. Safranine-T dye mixed with polyvinyl
alcohol (PVA) solution was deposited on a conducting and transparent indium-tin-oxide (ITO)-coated glass that was used as
one electrode and another ITO-coated glass as the counterelectrode. A solid polymeric electrolyte consisting of polyethylene
oxide-ammonium perchlorate-ethylene carbonate and propylene carbonate with suitable weight ratio was prepared and sandwiched
between these two ITO-coated glass electrodes, which were separated by a Teflon spacer about 50 μm thick. The cell was biased
with a direct current source to make the dye and PVA-coated ITO as the anode and the other ITO as the cathode. On illumination
by a tungsten lamp, from the cathode side, the change of photocurrent was measured. The dark current-voltage characteristics
and the growth and decay of the photocurrent for steady and pulsed illumination were studied. 相似文献