碳点的合成与表征及其在潜在手印显现中的应用  

Synthesis and Characterization of Carbon Dots and Its Applications in Latent Fingerprint Development

作　　者：范文卓 于卓弘 王猛[1] 李杰 杜怡泽 李明[1] 袁传军 FAN Wen-Zhuo;YU Zhuo-Hong;WANG Meng;LI Jie;DU Yi-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,沈阳110035

出　　处：《分析化学》2024年第4期492-503,共12页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.21205139,21802169);辽宁省应用基础研究计划项目(No.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(Nos.LJKZ0068,LJKZ0076,LJKMZ20220384);中国刑事警察学院2023年研究生创新能力提升项目(Nos.2023YCYB45,2023YCYB46)资助。

摘　　要：以柠檬酸和尿素为反应原料、乙二醇为反应溶剂,采用溶剂热法合成了荧光碳点(Carbon dots,CDs),并对CDs的形貌、粒径、晶体结构、元素成分、表面基团和光学性质等进行了表征。研究了CDs对激发光依赖的荧光发射特性,讨论了反应温度、反应时间和原料比例等合成条件对CDs的激发波长和发射波长的影响。将CDs与淀粉、纳米二氧化硅、蒙脱土、高岭土、硅藻土和氧化镁6种基质复合,制备出一系列CDs荧光复合物。最终将CDs-淀粉荧光复合物应用于光滑客体表面潜在手印的增强显现,并从定性和定量两个层面对显现效果进行了详细评价。利用CDs-淀粉荧光复合物对激发光依赖的荧光发射特性,结合滤光拍照,在很大程度上降低了客体背景噪声干扰。手印显现结果表明,显现信号与客体背景噪声之间的对比反差明显,具有较强的显现对比度;显现手印的各级特征反映清晰,具有较高的显现灵敏度;显现粉末与手印遗留物质之间的结合程度较高,具有较好的显现选择性。Fluorescent carbon dots(CDs)were synthesized via a solvothermal method with citric acid and urea as raw materials,and ethylene glycol as reaction solvent.The micromorphology,crystal structure,elemental composition,surface functional group,and optical property of as-synthesized CDs were characterized.The excitation-dependent fluorescence property of CDs was investigated,and the effects of synthesis conditions including reaction temperature,reaction time and raw materials on excitation and emission wavelengths of the CDs were also discussed.Then,a series of CDs-based fluorescent composites were prepared by combining CDs with starch,nano-silica,montmorillonite,kaoline,kieselguhr and magnesium oxide,respectively.Finally,the CDsstarch composites were used for latent fingerprint development on smooth substrates,and the qualitative as well as quantitative evaluation of the contrast,sensitivity and selectivity in fingerprint development were also made.Enhanced development of latent fingerprints was thus achieved by the aid of the excitation-dependent fluorescence property of CDs-starch composite combined with the optical filtering technique,which could decrease the background noise interference to a great extent.Experimental results showed that,the contrast between fingerprint(developing signal)and substrate(background noise)was obvious,exhibiting a strong contrast;the minutiae of papillary ridges were clear,indicating a high sensitivity;the adsorption between CDs-starch composites and fingerprint residues was specific,showing a good selectivity.

关 键 词：碳点 荧光 纳米材料 潜在手印 手印显现 

分 类 号：D918.91[政治法律—法学] TB383.1[一般工业技术—材料科学与工程]