具有磁响应性的纳米复合中空介孔硅球的制备及其显现潜指纹的研究

The fingerprint has been recognized as the important evidence at the crime scene. Latent fingermarks are one of the most useful forms of physical evidence in identification and generalized proof of identity. Nowadays, nanotechnology is currently being used in fingerprint detection, which is greatly accelerating both the rate and accuracy of solve a case. To compensate for the deficiencies of synthesized material，which currently being used in the fingerprint detection of permeable and non-permeable surface. In this project, we plan to synthesize magnetic hollow mesoporous silica nanospheres by an electrostatic self-assembly templated approach, which are available for use as carriers loaded gold nanoparticles. We intend to use strong adsorption of gold nanoparticles for the sweat and grease of latent fingerprints, and combine synergistic effect of gold nanoparticles、the iron oxide nanoparticles and hollow mesoporous silica nanospheres in the fingerprint detection. A novel recyclable nanocomposite will be designed and synthesized with magnetic responsibility, which used to detect latent fingerprints. The findings will reveal the impact of nanomaterials on detect latent fingerprints from the composition, structure, morphology and magnetic of synthetic material. By optimizing reaction conditions, we want to find the best way to latent fingerprints detection. The research result of this project has an important scientific significance for fabricating novel nanocomposite for latent fingerprints detection and promotion its opportunities in establish a non-toxic, simple and wide application method of latent fingerprint detection, and even has important significance in the investigation for criminal case.

指纹曾被司法界公认为“证据之首”。潜指纹鉴定是刑侦工作者进行人身认定的首选，是直接的物证来源。纳米技术在潜指纹检测方面的应用，将大大加快案件破获速度并提高其准确率。本项目针对已合成材料在渗透性和非渗透性表面显现潜指纹的不足，通过静电自组装模板法制备复合中空介孔磁性纳米硅球，并以此为载体负载纳米金粒子。利用球形的纳米金对潜指纹中的汗液或附着的油脂的强吸附作用，结合纳米金、纳米四氧化三铁和中空介孔纳米硅球之间的协同效应促使多种客体表面不同类型的潜指纹快速显现，制备一种具有磁响应性的可重复回收利用的用于潜指纹显现的新型高效纳米复合材料。研究纳米复合材料的组成、结构、形貌及磁性对潜指纹显现的影响，探索在温和条件下显现不同客体表面的（渗透性和非渗透性表面）潜指纹。本项目对发展新型高效的用于显现潜指纹的纳米材料，建立无毒、操作简单、应用广泛的潜指纹显现方法提供新的机遇，也对实际案件的侦查具有重要意义。

指纹又称为指印，是人身认定的首选。19 世纪末，美国著名的“威斯特案件”就是通过指纹鉴定，从11项人身测量数据完全相同的两个嫌疑人中发现并确定罪犯的。因此，对遗留在不同客体表面上指纹的提取及显现是刑侦工作者研究的重点。潜指纹在通常情况下难于分辨和发现，对侦破案件有着重要意义。但是，传统的潜指纹显现法往往存在显现时间长、显现效果不佳等缺点，利用新型纳米技术进行潜指纹鉴定则具有高效、无毒、无损、价廉等突出优点。纳米材料在潜指纹显现方面的应用，将大大加快案件破获速度并提高其准确率。针对已合成材料在渗透性和非渗透性表面显现潜指纹的不足，本项目开展了不同纳米复合材料的制备及其显现潜指纹的研究。分别通过静电自组装模板法、无模板溶剂热法、水热法制备了三种不同的纳米材料，即中空介孔磁性纳米硅球、中空磁性纳米球及介孔分子筛SBA-16，并以此为载体负载金纳米粒子。利用透射电镜、X射线粉末衍射、红外光谱、等离子体发射光谱及X射线光电子能谱仪等分析测试手段对三种不同纳米复合材料进行了表征。所制备的纳米复合材料形貌清晰，负载金的中空介孔磁性纳米硅球粒径约为250 nm，负载金的中空磁性纳米球粒径约为400 nm，负载金的分子筛SBA-16孔道结构明显，金纳米粒子粒径均约为10 nm。利用球形的金纳米粒子对潜指纹中的汗液或附着的油脂的强吸附作用，结合硅纳米材料巨大的负载量、较高的比表面积、良好的亲水性及四氧化三铁在外加磁场作用下不易破坏潜指纹纹线、易于回收利用等特性，所制备纳米复合材料被用于显现不同客体表面的潜指纹。主要选取玻璃为非渗透性表面，A4复印纸为渗透性表面，研究表明负载金的中空磁性纳米球和负载金的介孔分子筛SBA-16用粉末法均可清晰显现不同客体表面的潜指纹，负载金的中空介孔磁性纳米硅球则显现效果较差。本项目对发展新型高效的用于潜指纹显现的纳米材料，建立无毒、操作简单、应用广泛的潜指纹鉴定方法提供新的机遇，也对实际案件的侦查具有重要意义。