Dorakumbura Buddhika N, Becker Thomas, Lewis Simon W
Nanochemistry Research Institute, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia; Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
Nanochemistry Research Institute, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia; Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
Forensic Sci Int. 2016 Oct;267:16-24. doi: 10.1016/j.forsciint.2016.07.024. Epub 2016 Aug 3.
Crime scene investigations often rely on successful development of latent fingermarks for personal identification. In this context, exploring fundamental properties of latent fingermarks is vital for developing robust and more effective detection techniques. Here in a novel approach, PeakForce quantitative nanomechanical mapping (PF QNM) atomic force microscopy (AFM) has been used to study the variations in surface adhesion and topography of latent fingermark droplets over time. It was found that variation in adhesion was exhibited even across the surface of a single fingermark droplet, suggesting that individual droplets are heterogeneous in chemical composition on the nanoscale. The technique was successfully employed in observing the topographical variation of eccrine droplets, which has not been achieved using other optical microscopy techniques. In addition, the adhesion of fingermark droplets changed significantly as they aged. Propagation of a thin film of material from the fingermark ridges across the furrows, starting immediately after deposition, was captured in real-time, demonstrating the dynamic nature of the deposit. These results will aid in providing a more complete fundamental understanding of latent fingermark residue, allowing the more rational development of new detection techniques, especially those involving nanostructured materials.
犯罪现场调查通常依赖于成功提取潜在指纹以进行身份识别。在此背景下，探索潜在指纹的基本特性对于开发强大且更有效的检测技术至关重要。本文采用一种新颖的方法，利用峰值力定量纳米力学映射（PF QNM）原子力显微镜（AFM）来研究潜在指纹液滴的表面粘附力和形貌随时间的变化。研究发现，即使在单个指纹液滴的表面，粘附力也存在变化，这表明单个液滴在纳米尺度上的化学成分是不均匀的。该技术成功用于观察外分泌液滴的形貌变化，这是其他光学显微镜技术无法实现的。此外，指纹液滴随着时间推移其粘附力发生显著变化。从指纹脊部穿过沟槽的物质薄膜在沉积后立即开始传播，这一过程被实时捕捉到，证明了沉积物的动态特性。这些结果将有助于更全面地从根本上理解潜在指纹残留物，从而更合理地开发新的检测技术，特别是那些涉及纳米结构材料的技术。
