Arshad Ayesha, Farrukh Muhammad Akhyar, Ali Shaista, Khaleeq-ur-Rahman Muhammad, Tahir Muhammad Ashraf
Forensic Science Laboratory, Department of Chemistry, GC University Lahore, Lahore, 54000, Pakistan.
Punjab Forensic Science Agency, Thokar Niaz Baig, Multan Road, Lahore, Pakistan.
J Forensic Sci. 2015 Sep;60(5):1182-7. doi: 10.1111/1556-4029.12890.
Fingermarks are one of the most useful forms of evidence in identification and can provide generalized proof of identity in crime investigation. They are developed using various conventional powders. The novel nanopowder ZnO-SiO2 was synthesized via the conventional heating method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray (EDX) analysis, transmission electron microscope (TEM), and X-ray diffraction (XRD). The mean particle size of ZnO-SiO2 nanopowder calculated through TEM was 32.9 nm. The development of fingermarks was carried out by powder dusting and small particle reagent (SPR) methods. Powder dusting method was used for the development of latent fingermarks on various dry, nonporous, and semi-porous surfaces. The SPR method was also applied to wet nonporous surface. The developed latent fingermarks using ZnO-SiO2 nanopowder were found to have excellent quality with very clear third-level ridges detail and had better visibility than commercially available white powder.
指纹是身份识别中最有用的证据形式之一，在犯罪调查中可以提供通用的身份证明。它们通过各种传统粉末显现出来。新型纳米粉末ZnO-SiO₂通过传统加热方法合成，并通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、能量色散X射线（EDX）分析、透射电子显微镜（TEM）和X射线衍射（XRD）进行表征。通过TEM计算得出的ZnO-SiO₂纳米粉末的平均粒径为32.9纳米。指纹显现通过粉末刷显法和小颗粒试剂（SPR）法进行。粉末刷显法用于在各种干燥、无孔和半多孔表面上显现潜在指纹。SPR法也应用于潮湿的无孔表面。发现使用ZnO-SiO₂纳米粉末显现出的潜在指纹质量极佳，三级纹线细节非常清晰，并且比市售白色粉末具有更好的可见性。
