二氧化钛包覆碳点的合成、表征及手印显现应用研究  

Synthesis and Characterization of Titanium Dioxide Coated Carbon Dots and Their Applications in Fingerprint Development

作　　者：马榕蔚 王猛[1] 李杰 徐致泽 李明[1] 袁传军 MA Rong-wei;WANG Meng;LI Jie;XU Zhi-ze;LI Ming;YUAN Chuan-jun(College of Forensic Sciences,Criminal Investigation Police University of China,Shenyang 110035,China)

机构地区：[1]中国刑事警察学院刑事科学技术学院,辽宁沈阳110035

出　　处：《光谱学与光谱分析》2025年第5期1325-1333,共9页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21205139);辽宁省应用基础研究计划项目(2023JH2/101300097);辽宁省2020年百千万人才工程项目;辽宁省教育厅科学研究经费项目(LJKZ0068,LJKMZ20220384);辽宁省教育科学“十四五”规划2024年度课题(JG24DB482);中国刑事警察学院2024年研究生创新能力提升项目(2024YCYB41)资助。

摘　　要：潜在手印是案件现场中常见的痕迹物证,对其清晰显现是手印分析与鉴定的重要前提。本研究制备了二氧化钛包覆的碳点(CDs@TiO2)纳米荧光悬浮液,并用于潜在手印的高质量显现。首先,以柠檬酸和尿素为原料,以N,N-二甲基甲酰胺为溶剂,采用溶剂热法合成碳点(CDs)。接着,利用氨水催化钛酸四丁酯水解,在CDs表面进一步包覆TiO2,得到CDs@TiO2纳米材料,并优化了合成条件。合成条件优化为:CDs用量3.0 mL、钛酸四丁酯用量1.5 mL、水用量1.5 mL、氨水用量0.1 mL、反应温度50℃、滴加时间30 min。然后,表征了CDs和CDs@TiO2的形貌、成分、结构、光学等性质。表征结果显示:CDs为类球形,平均粒径7.54 nm,能够产生CDs的特征拉曼散射峰及红外吸收峰,具有六方晶系石墨的晶体结构,在343 nm处有最强紫外吸收,最大荧光激发波长450 nm,最大荧光发射波长567 nm;CDs@TiO2为不规则球形,平均粒径114.85 nm,能够同时产生CDs和TiO2的特征拉曼散射峰及红外吸收峰,同时具有六方晶系石墨和四方晶系金红石型TiO2晶体结构,在321 nm处有最强紫外吸收,最大荧光激发波长387 nm,最大荧光发射波长529 nm。最后,将CDs@TiO2配制成悬浮液,提出了基于疏水作用的手印显现方法,优化了显现条件,考察了手印显现的效果。显现条件优化为:十二烷基硫酸钠浓度1.0‰~2.0‰、氯化胆碱浓度4.0‰~6.0‰、显现时间10~20 s。显现结果表明:在490 nm波段光源的激发下并配合黄色滤光片,手印产生明亮的蓝色荧光,粉末选择吸附于乳突纹线,纹线连贯清晰,细节特征明显,具有较高的显现对比度、灵敏度和选择性。该研究提出的基于CDs@TiO2纳米荧光悬浮液的手印显现方法适用于光滑非渗透性客体表面潜在手印的高质量显现,具有广泛的适用性。Latent fingerprints(LFs)are commonly encountered at crime scenes.Developing the LFs clearly is the precondition for further analysis and identification.In this work,titanium dioxide-coated carbon dots(CDs@TiO2)fluorescent nanosuspensions were prepared and used for high-quality LF development.Firstly,carbon dots(CDs)were synthesized via a solvothermal approach using citric acid and urea as raw materials and N,N-dimethylformamide as solvent.Then,CDs@TiO2 nanomaterials(NMs)were formed by coating CDs with a layer of TiO2 shell based on the ammonia-catalyzed hydrolysis of titanium butoxide,and the synthesis conditions were optimized.The optimized synthesis conditions were as follows:the amount of CDs,tetrabutyl orthotitanate,water,and ammonium hydroxide was 3.0,1.5,1.5,and 0.1 mL,respectively,the reaction temperature was 50℃,and the dropping period was 30 min.After that,the morphology,composition,structure,and optics properties of CDs and CDs@TiO2 NMs were characterized.Characterization results showed that,CDs were near spherical with an average diameter of 7.54 nm,they could give characteristic Raman scattering peaks as well as infrared absorption peaks of CDs,and possessed the crystal structure of hexagonal graphite,their UV absorption peak was at 343 nm,and their maximum fluorescence excitation and emission wavelength was at 450 and 567 nm respectively;CDs@TiO2 were irregularly spherical with an average diameter of 114.85 nm,they could give characteristic Raman scattering peaks as well as infrared absorption peaks of both CDs and TiO2,and possessed the crystal structure of both hexagonal graphite and tetragonal rutile TiO2,their UV absorption peak was at 321 nm,and their maximum fluorescence excitation and emission wavelength was at 387 and 529 nm respectively.Finally,CDs@TiO2 NMs were made into nanosuspension for developing LFs via hydrophobic interaction.The development conditions were optimized,and the results of LF development were investigated in detail.The optimized development conditions were as follows:th

关 键 词：手印显现 潜在手印 荧光 碳点 二氧化钛 纳米材料 

分 类 号：O657.3[理学—分析化学]