潜指纹的显现及电化学成像新方法研究

发布时间：2018-06-06 13:13

本文选题：潜指纹 + 指纹显现　；参考：《北京科技大学》2018年博士论文

【摘要】：指纹鉴定是进行个人识别的最可靠的方法之一,在法庭科学、涉密系统、户籍、社保等领域都有广泛的应用。肉眼不可见的指纹称为潜指纹,是最常见也是刑侦科学领域最重要的指纹。潜指纹检验技术分为四个步骤,潜指纹的显现、指纹图像采集、指纹比对鉴定和数据库查询。虽然诸多方法被用于潜指纹显现检测中,但是在获取指纹信息时,简单、快速、易操作、高分辨率和适用客体范围广的显现技术在许多情况下仍然存在挑战。另外,该领域近些年的研究热点方向是对指纹残留物中化学成分的检测。除了物理形貌的细节特征以外,指纹残留物的化学成分还提供了其他极具价值的信息,例如通过对指纹化学成分的检测判断指纹遗留者的年龄,性别,病史和可能的药物习惯等。指纹图像采集最为常用的技术是拍照法,但是拍照对指纹样品、照相设备要求较高,提取的指纹图像质量与拍照人员、现场光线等关系较大。本论文的研究是围绕解决潜指纹显现中的难题和发展新的指纹图像采集方法开展的创新性研究。首先,针对目前指纹显现领域中的疑难问题,利用潜指纹残留物和高分子纤维素膜表面亲水性的差异,开发了一种简单快速可以应用于不同的基底性质和指纹类型的潜指纹显现新方法。通过简单地将亲水性纤维素膜与染料水溶液相结合的方式,在3～5 s内高分辨率地显现位于多种客体表面的潜指纹。应用该方法可以观察到在纤维素膜表面的潜指纹的二级和三级水平特征,清晰度非常高,可以用于个人身份识别目的。对从多种常见客体(如玻璃,彩色纸盒,陶瓷杯)和疑难客体(如纸币,人体皮肤和皮革)表面使用指纹胶带提取的潜指纹显现效果也非常的高效。此外,这种方法也适用于长达16天的陈旧潜指纹和自然潜指纹。该潜指纹显现方法灵敏度非常高,在醋酸纤维素膜表面连续捺印8次的潜指纹使用这种方法显现仍能获得清晰的细节特征。与传统方法相比,这种指纹显现方法简单、快速、通用、安全、无损、成本低、分辨率高,因此在个人身份验证相关应用中表现出良好的潜力。针对不能直接在现场显现的客体表面潜指纹,目前一般采取警用胶带进行提取,这种方法的主要问题是不适合某些脆弱材料,而且对某些指纹破坏较大。为了解决这一问题,在上述方法的基础上,开发了一种可以用于同时转移和显现多种客体表面的潜指纹的新方法。这种方法通过将硝酸纤维素(NC)膜或聚偏二氟乙烯(PVDF)膜与亚甲基蓝(MB)溶液/银染溶液结合,可以用于同时转移和高分辨率显现多种客体表面的潜指纹。转移、显现步骤简单,在几分钟内可以清晰显现从客体表面转移来的潜指纹。对从各种常见客体(如玻璃,广告纸,陶瓷杯)和疑难客体(人体皮肤和皮革)表面转移的潜指纹进行显现非常有效。此外,该方法能够在转移指纹之后,通过使用相应抗体修饰的金纳米颗粒和银染处理特异性地显现指纹,在身份识别之外还能获取指纹成分中额外的化学信息。这种转移显现方法简单,快速,安全,成本低,适用客体广泛,分辨率高,对客体没有破坏性,并对转移之后的分析无影响,因此该方法在个人身份验证领域和代谢物检测方面具有良好的潜力。最后,针对目前缺乏对指纹先进行无标记显现,再进一步进行指纹化学图像采集的研究现状,首次开发了使用扫描电化学显微镜(SECM)对无标记的潜指纹进行高分辨率化学图像采集的方法。这种方法克服了传统的光学图像采集方法受客体背景颜色影响的问题,分辨率高。SECM探针在表面询问模式下工作,通过可逆的氧化还原媒介体甲基紫精(MV2+)对NC膜表面的指纹残留物(如角鲨烯等)进行化学成分成像。甲基紫精(MV2+)在探针尖端被还原为MV'+ MV·+扩散到NC膜表面与指纹成分发生反应。MV'+被氧化为MV2+,产生的MV2+扩散到电极附近。当探针位于脊线区上方时,由于甲基紫精与指纹成分发生反应,MV2+浓度升高,使氧化还原反应加快,探针电流相比稳态电流增大;当探针位于谷线区上方时,由于MV2+扩散被阻碍,探针电流减小。当探针对基底表面进行扫描时,探针尖端电流的变化反映了基底表面指纹化学成分的分配情况从而反映出其形貌状况。通过这种方法,无标记油潜指纹、亚甲基蓝增强的油潜指纹、自然潜指纹、血指纹、陈旧指纹和从客体表面转移的油潜指纹等多种指纹类型都能得到高分辨率的指纹成分化学成像。应用SECM对指纹成分进行化学成像的图像可以提供常规光学方法无法获得的指纹残留物化学成分的宝贵信息。该方法提供了一种全新的指纹成分化学图像采集方式,可以提供除指纹形貌以外指纹遗留者更丰富的化学信息,解决了目前指纹鉴定领域化学信息和物理形貌同时收集的技术缺乏难题。
[Abstract]:Fingerprint identification is one of the most reliable methods for personal identification. It is widely used in the fields of forensic science, secret related systems, household registration, social security and other fields. The invisible fingerprint of the naked eye is called the latent fingerprint. It is the most common fingerprint in the field of criminal investigation. The technique of latent fingerprint examination is divided into four steps, the appearance of latent fingerprints, and the fingerprints. Such as collection, fingerprint comparison identification and database query. Although many methods are used in the detection of latent fingerprint, it is simple, fast, easy to operate, high resolution and wide range of object range in many cases. In addition to the detailed features of physical morphology, the chemical composition of the fingerprints also provides other valuable information, such as the age, sex, medical history and possible drug habits of the fingerprints, such as the detection of the chemical components of the fingerprint. The operation is the method of taking pictures, but the requirement of the photo of the fingerprint sample and the photographic equipment is high. The quality of the extracted fingerprint image is closely related to the photographers and the field light. The research of this paper is an innovative study on solving the problems in the appearance of the latent fingerprint and developing the new fingerprint image acquisition method. The difficult problem in the domain is to develop a new method that can be easily applied to different substrate properties and fingerprint types by using the difference of the hydrophilic property of the latent fingerprint residue and the surface of the polymer cellulose membrane. By combining the hydrophilic cellulose membrane with the dye solution in a simple way, the high resolution in 3~5 s is made. The application of this method can observe the two and three level characteristics of the latent fingerprint on the surface of the cellulose membrane, which is very high in definition and can be used for personal identification purposes. In addition, this method is also suitable for 16 days old latent fingerprints and natural latent fingerprints. The latent fingerprint method is very sensitive, and the method of using the latent fingerprint of 8 times on the surface of cellulose acetate membrane is still clear. Compared with the traditional method, the fingerprint method is simple, fast, universal, safe, nondestructive, low cost and high resolution, so it has a good potential in the application of personal identity verification. The main problem of the method is that it is not suitable for some fragile materials and is very destructive to some fingerprints. In order to solve this problem, a new method is developed on the basis of the above method, which can be used to transfer and display the latent fingerprints on the surface of various objects at the same time. This method is by using the NC membrane or pending two fluoroethylene (PVDF). The membrane is combined with the methylene blue (MB) solution / silver dye solution and can be used for simultaneous transfer and high resolution of the latent fingerprints on a variety of object surfaces. The transfer is simple and can clearly show the latent fingerprints transferred from the object surface in a few minutes. The latent fingerprints of the skin and leather surface transfer are very effective. In addition, the method can obtain additional chemical information from the identification of the fingerprint by using the gold nanoparticles and silver dyes modified by the corresponding antibody after the transfer of fingerprints, and the additional chemical information in the fingerprint composition can be obtained outside the identification. This transfer method is simple, Fast, safe, low cost, wide application object, high resolution, no destructiveness to the object, and no influence on the analysis after the transfer. Therefore, the method has good potential in the field of personal identification and the detection of metabolites. Finally, the lack of unmarked appearance of finger print and further fingerprint chemical map The method of high resolution chemical image acquisition for unmarked latent fingerprints by scanning electrochemical microscopy (SECM) is developed for the first time. This method overcomes the problem that the traditional optical image acquisition method is affected by the background color of the object, and the high resolution.SECM probe works in the surface inquiry mode. A reversible oxidation-reduction vector, methyl violet (MV2+), is used to make a chemical composition of the fingerprint residues (such as squalene) on the surface of the NC membrane. Methyl violet (MV2+) is reduced to MV'+ MV + at the tip of the probe and diffused to the surface of the NC membrane to react with the composition of the fingerprint, and.MV'+ is oxidized to MV2+, and the resulting MV2+ spread to the electrode. When the probe is located in the ridge, the probe is located in the ridge. When the concentration of methyl violet is reacted with the fingerprint, the increase of MV2+ concentration makes the redox reaction expedite and the probe current increases compared with the steady current. When the probe is above the valley line area, the probe current decreases as the MV2+ diffusion is hindered. When the probe is scanned on the substrate surface, the change of the probe tip current is reflected. In this way, a high resolution fingerprint composition can be obtained by this method: unlabeled oil latent fingerprints, methylene blue enhanced oil latent fingerprints, natural latent fingerprints, blood fingerprints, old fingerprints, and oil latent fingerprints transferred from the surface of the object. Images of chemical imaging of fingerprint components using SECM can provide valuable information on the chemical composition of fingerprint residues that are not obtained by conventional optical methods. This method provides a new method of fingerprint composition chemical image acquisition, which can provide more abundant chemical information from fingerprints except fingerprints, and solve the problem. The technology of simultaneous collection of chemical information and physical morphology in the field of pre fingerprint identification lacks the difficulty.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2018
【分类号】：D918.91;O657.1

【参考文献】