近场激光热透镜光谱法测定催化反应动力学参数的研究

激光热透镜光谱法(LTLS)是一种高灵敏光热光谱分析技术,可测定10－’~10－’吸光度[‘j．LTLS既可     

激光热透镜光谱分析法*

激光热透镜光谱法是20世纪80年代发展起来的一种光热光谱分析技术。该法以其高灵敏度、低检出限以及适应于微、少量样品分析等特点引 分析工作者的极大兴趣。本文从测量装置、理论、痕量无机物和有机物测定以及与其它分析技术的联用等方面对1990年以来激光热透镜光谱分析法的进展作了较为详细的综述。     

高效毛细管电泳中的激光光热检测技术

集中介绍了激光光热分析在高效毛细管电泳检测上的应用；分析了各种光热检测构型的特点，阐述了影响光热信号的各种因素；指出了激光光热检测技术在高效毛细管电泳中的应用前景。     

激光光热折射光谱法及其差分构型的研究

本工作借助于透镜对探测束发散的会聚补偿作用,设计了一个光热折射光谱的差分式光路构型,可以有效地消除溶剂空白吸收的影响和泵浦激光强度起伏与指向噪音的影响。本差分构型光路简单,容易实现样品池和参考池的定位与调整。文章还详细讨论了光热折射光谱法的实验参数,获得的结晶紫和钴的检测下限分别为1.0×10~(-9)mol/L和0.28 μg/ml,对应的最小吸光度为1.5×10~(-8)和2.5×~(-7)。     

激光分析的研究进展

激光分析是现代分析化学的前沿领域之一。本文基于激光与物质作用产生的发射、散射、吸收和电离等特性,对激光诱导荧光光谱、激光拉曼光谱、激光光声光谱、激光光热光谱和激光电离光谱等激光分析方法的研究进展和应用进行了综述。     

不同形貌普鲁士蓝纳米粒子的合成及光热性能

制备了立方体、直角立方体、球形、棒状、中空状、核壳状、梭形、多面体等8种不同形貌的普鲁士蓝纳米粒子,利用扫描电子显微镜、透射电子显微镜、紫外-可见分光光度计等对纳米粒子进行了表征,考察了普鲁士蓝纳米粒子光热性能的影响因素.结果表明,普鲁士蓝纳米粒子的形貌与光热性能之间联系密切,粒子形貌不同,光热性能不同;当外部实验条件一定时,纳米粒子的形貌、大小、吸收横截面积、尖锐化程度及密实程度等对其光热性能有很大的影响;当纳米粒子形貌一定时,外部因素如激光器的选择、激光功率密度及纳米粒子的浓度等直接影响普鲁士蓝纳米粒子的光热性能;在相同浓度下,激光功率密度越大,纳米粒子的升温效果越明显,光热性能越好;而激光功率密度不变时,纳米粒子浓度越大,其光热转换效率越高.     

近红外光镊技术结合脂质体膜相变用于硅-金核壳纳米粒子热效应的研究

通过测定近红外光镊捕获的单个硅-金核壳纳米粒子对荧光标记的脂质体膜加热产生的相变,建立了一种对纳米粒子的激光热效应的三维稳态测定方法。考察了介质温度和激光功率等因素对纳米粒子热效应的影响,并对硅-金核壳纳米粒子和纳米金的光热转换效率进行了比较,结果表明硅-金核壳纳米粒子的光热转换效率最高,其表面温度和光镊激光功率呈正相关(激光功率为0.6 W时,其表面温度达200℃以上)。最后对这类核壳纳米粒子具有良好热效应的原因进行了理论分析。本文建立的方法和获得的结果有助于深入了解硅-金核壳纳米材料的热效应,并展示了这类材料在癌症光热治疗等方面的应用前景。     

激光光热反射光谱检测装置的研制

研制出一种采用直接测量激光反射光信号的激光光热反射光谱检测装置。讨论了该装置的硬件结构和程序模块,并应用于分子印迹实验。该装置具有操作简单、精度高、稳定性好和抗干扰能力强等优点。     

激光原子荧光光谱分析法的进展

概述了激光原子荧光光谱分析法的研究现状和发展趋势。对各种原子化学方法与激光原子荧光光谱分析法相结合的分析特性进行了描述，着重介绍了电热原子化作为原子化器的激光原子荧光光谱法近年来的发展和应用。     

阻抑光度法测定痕量铁(Ⅲ)

铁是人体不可缺少的微量元素,是血红蛋白的核心部分,正常成人体内铁的总量为2~4g。目前,测定痕量铁的方法有伏安法[1]、化学发光法[2]、色谱法[3]、极谱法[4]、原子吸收光谱法[5]、激光光热折射光谱法[6]、微晶石蜡柱固相萃取法[7]、二阶导数光谱-峰面积积分光度法[8]和分光光度法[9]等。阻抑动力学分光光度法是利用具有氧化性的物质如高碘酸钾、过氧化氢、三价铁离子、溴酸钾等,对在不同波     

Photothermal performance of MFe2O4 nanoparticles

Photothermal therapy (PTT) has emerged as one of the promising cancer therapy approaches. As a representative photothermal agent (PTA), magnetite possesses many advantages such as biodegradability and biocompatibility. However, photothermal instability hampers its further application. Herein, we systematically synthesized three kinds of ferrite nanoparticles and detailedly investigated their photothermal effect. Compared with Fe₃O₄ and MnFe₂O₄ nanoparticles, ZnFe₂O₄ nanoparticles exhibited a superior photothermal effect. After preservation for 70 days, the photothermal effect of Fe₃O₄ and MnFe₂O₄ nanoparticles observably declined while ZnFe₂O₄ nanoparticles showed slight decrease. Furthermore, in vitro experiment, ZnFe₂O₄ nanoparticles showed little toxicity to cells and achieved outstanding effect in killing cancer cells under NIR laser irradiation. Overall, through synthesizing and studying three kinds of ferrite MFe₂O₄ nanoparticles, we obtained ferrites as PTAs and learned about their changing trend in photothermal effect, expecting it can inspire further exploration of photothermal agents.     

Photothermal performance of MFe2O4 nanoparticles

In this paper, we synthesized three kinds of ferrites and investigated their photothermal property. The result indicated that the photothermal effect of Fe₃O₄ and MnFe₂O₄ nanoparticles declined while that of ZnFe₂O₄ nanoparticles maintained relatively stable after preservation for 70 days, and then ZnFe₂O₄ nanoparticles could effectively kill cancer cells under NIR laser.     

一种具有光热转换功能的复合薄膜

通过熔融加工和挤出吹塑的方法,制备了反式聚-1,4-异戊二烯(TPI)含量分别为1%、5%和9%的TPI/LLDPE复合薄膜。将复合薄膜置于60℃的饱和碘蒸气中处理,制备得到具有光热转换功能的薄膜。结果表明,复合薄膜中TPI含量越高,经碘蒸气处理后所得薄膜的光热转换能力越强。在功率为0. 9W的激光照射3min后,具有光热转换功能的薄膜表面的温度升高值最大达35℃。     

Photothermal Conversion of Hydrogel-Based Biomaterial

Traditional energy from fossil fuels like petroleum and coal is limited and contributes to global environmental pollution and climate change. Developing sustainable and eco-friendly energy is crucial for addressing significant challenges such as climate change, energy dilemma and achieving the long-term development of human society. Biomass hydrogels, which are easily synthesized and modified, have diverse sources and can be designed for different applications. They are being extensively researched for their applications in artificial intelligence, flexible sensing, biomedicine, and food packaging. The article summarizes recent advances in the preparation and applications of biomass-based photothermal conversion hydrogels, discussing the light source, photothermal agents, matrix, and preparation methods in detail. It also explores the use of these hydrogels in seawater desalination, photothermal therapy, antibacterial agents, and light-activated materials, offering new ideas for developing sustainable, efficient, and advanced photothermal conversion biomass hydrogel materials. The article concludes with suggestions for future research, highlighting the challenges and prospects in this field and paving the way for developing of long-lasting, efficient energy materials.     

Photothermal ablation of amyloid aggregates by gold nanoparticles

Amyloid peptide (Aβ) is found in the brain and blood of both healthy and diseased individuals alike. However, upon secondary structure transformation to a β-sheet dominated conformation, the protein aggregates. These aggregates accumulate to form neuritic plaques that are implicated in the pathogenesis of Alzheimer's disease. Gold nanoparticles are excellent photon-thermal energy converters. The extinction coefficient of the surface plasmon band of gold nanoparticles is very large when compared to typical organic dyes. In this study, gold nanoparticle–Aβ conjugates were prepared and the photothermal ablation of amyloid peptide aggregates by laser irradiation was studied. Monofunctional gold nanoparticles were prepared using a recently reported solid phase modification method and then coupled to fragments of Aβ peptide, namely Aβ(31–35) and Aβ(25–35). The conjugates were then mixed with Aβ fragments in solution. The aggregated peptide formation was studied by a series of spectroscopic and microscopic techniques. The peptide aggregates were then irradiated by a continuous laser. With gold nanoparticle–Aβ conjugates present the aggregates were destroyed by photothermal ablation. Gold nanoparticles without Aβ conjugation were not incorporated into the aggregates and when irradiated did not result in photothermal ablation. With gold nanoparticle–Aβ conjugates the ablation was selective to the site of irradiation and minimal damage was observed as a result of thermal diffusion. In addition to the application of photoablation to a protein-based sample the nanoparticles and the chemistry involved provide an easily monofunctionalized photothermal material for the biological conjugation.     

Progress and Prospect of Photothermal Catalysis

Recently, solar-driven synthesis due to its energy-saving and environmentally friendly advantages has attracted more and more attention, whereas the low solar-to-chemical conversion efficiency significantly hindered its development. New effective options that fully utilize full-band sunlight are urgently needed. Novel photothermal catalysis combined with the advantages of photocatalysis and thermalcatalysis can improve the utilization efficiency of solar energy and lower the reaction temperature, thus becoming a promising technology. This review divides photothermal catalysis into photo-assisted thermalcatalysis, thermal-assisted photocatalysis, and photothermal synergistic catalysis. Furthermore, the catalytic mechanical understanding of how photothermal affects the catalytic property of different applications(e.g., water splitting, CO₂/N₂ reduction, and environmental treatment) was also summed up and discussed in detail. The discussion ends with unsolved challenges in photothermal catalysis, particularly emphasizing the effect of temperature or sunlight on catalytic performance.     

Photothermal microscopy applied to the study of polymer composites

It is proposed to transfer the capabilities of a high sensitivity photothermal technique, developed by the group and widely used in the study of thermal properties of ceramics, metals and glass, to the study of polymer composites. The technique uses a sensing beam for the measurement of the thermal response of the sample due to local effects induced by heating with a modulated pump laser. With a simple spatial sweep of the beams on the sample surface, information on a micrometric scale of the thermal diffusivity of the material, distribution of phases and pores is obtained. Post-process analysis allows calculating average values of relevant properties such as thermal diffusivity, degree of crystallinity and distribution of aggregates. These measurements are performed at low laser powers (of the order of micro watts) avoiding the damage of the studied samples and turning this technique into a powerful tool of non-destructive characterization.     

A Supramolecular Naphthalene Diimide Radical Anion with Efficient NIR-II Photothermal Conversion for E. coli-Responsive Photothermal Therapy

We report a supramolecular naphthalene diimide (NDI) radical anion with efficient NIR-II photothermal conversion for E. coli-responsive photothermal therapy. The supramolecular radical anion (NDI-2CB[7])⋅⁻, which is obtained from the E. coli-induced in situ reduction of NDI-2CB[7] neutral complex, formed by the host–guest interaction between an NDI derivative and cucurbit[7]uril (CB[7]), exhibits unexpectedly strong NIR-II absorption and remarkable photothermal conversion capacity in aqueous solution. The NIR-II absorption is caused by the self-assembly of NDI radical anions to form supramolecular dimer radicals in aqueous solution, which is supported by theoretically predicted spectra. The (NDI-2CB[7])⋅⁻ demonstrates excellent NIR-II photothermal antimicrobial activity (>99 %). This work provides a new approach for constructing NIR-II photothermal agents and non-contact treatments for bacterial infections.