Light It Up: A Nanotechnology Approach for the Acquisition of Forensic Evidence

想象一下，你正在看一个破案电视节目。法医在犯罪现场发现了一条牛仔裤。他们用一种溶液喷洒他们，点燃他们的“火炬”，嘿，转眼间，血液，精液和唾液就变成了明亮的发光点，每个点都有不同的颜色。科学家们能够识别出存在的是什么，然后分别采集每种体液的样本，以获得沉积每种体液的人的DNA图谱。这是现实吗？不，远非如此。目前，进行不同的分析（每种分析需要不同的化学品和设备）来检测和识别每种体液。这是非常耗时的--这是警察等待可能有助于他们破案的结果时的一个重要因素。目前的方法也很难检测到微量的体液。鉴于现在可以从单个细胞中获得DNA图谱，在犯罪现场收集DNA痕迹至关重要。我们建议的研究旨在通过生产一种溶液使电视虚构成为现实，当将该溶液喷洒在法医证据物品上时，将使任何血液，精液或唾液的痕迹发出荧光，以便法医科学家能够轻松确定体液的位置（而且，重要的是，哪些是存在的），以便他们可以删除它们进行DNA分析。我们的解决方案被称为“点亮它”，它是基于被称为纳米颗粒的微小颗粒。每个纳米颗粒将被抗体（识别并结合另一个伴侣分子的生物分子）包裹，这些抗体将特异性地结合到一种体液上。抗体上会有荧光标签，当专业的法医光源照射在物品上时，体液所在的区域会发出不同颜色的荧光，每种颜色代表一种特定的目标液体。例如，精液将显示为蓝色，唾液为绿色，血液为红色。了解哪种体液存在可以为警方调查提供重要的佐证，有助于支持或反驳嫌疑人、受害者或证人的陈述。“点亮它”将很容易提供这些信息。由于我们的技术使用纳米颗粒，我们可以利用某些尺寸尺度特性来提高“Light It Up”的检测灵敏度。在磁铁的存在下，铁纳米粒子是磁性的。因此，如果纳米颗粒没有结合到生物流体上，它们可以简单地使用磁铁去除。随着“点亮它”的非绑定粒子被移除，绑定粒子将更容易显示出来。我们还计划开发一种“Light It Up”解决方案，直接在原位检测DNA。这是法医科学家在寻找生物体液时真正寻找的DNA（尽管他们也希望获得有关体液类型的信息，以帮助警方进行调查）。最后，我们希望决定是否可以利用“点亮警灯”，向警方提供资料，以指导他们进行调查。例如，我们要确定我们是否能够在犯罪现场留下的指纹中检测出爆炸物残留物，以及在指纹和体液中检测出毒品和毒品代谢物残留物。我们的抗体纳米粒子技术会特别结合这些目标，发出荧光信号，使警方能够集中搜寻处理爆炸物或交易及/或使用毒品的人。这些资料无疑会为警方的调查指明正确的方向。

Imagine you are watching a crime-solving TV programme. The forensic scientists have found a pair of jeans at a crime scene. They spray them with a solution, shine their 'torches' and, hey presto, blood, semen and saliva show up as brightly glowing spots each of a different colour. The scientists are able to identify what is present and then take a sample of each body fluid separately to obtain the DNA profile of the person who deposited each fluid. Is this reality? No. Far from it. Currently, a different analysis (each requiring different chemicals and equipment) is carried out to detect and identify each of these body fluids. This is very time consuming - an important factor when police are waiting for results which may help them solve a crime. The current methods also struggle to detect small traces of body fluids. Given that it is now possible to obtain a DNA profile from a single cell, collecting traces of DNA at crime scenes is vital.Our proposed research aims to make TV fiction a reality by producing a solution which, when sprayed on items of forensic evidence, will cause any traces of blood, semen or saliva to fluoresce, so that forensic scientists are readily able to identify where the body fluids are located (and, importantly, which ones are present) so that they can remove them for DNA profiling. 'Light It Up', as our solution is called, is based on minute particles called nanoparticles. Each nanoparticle will be coated with antibodies (biological molecules which recognise and bind to another partner molecule) which will specifically bind to only one body fluid. The antibodies will have fluorescent tags on them so that when specialist forensic light sources are shone on the item, the area where the body fluids are located will fluoresce with different colours, each colour representing a particular target fluid. For example, semen will show up as blue, saliva as green and blood as red. Knowing which body fluid is present can provide vital corroborative evidence for police investigations helping to support or refute suspect, victim or witness statements. 'Light It Up' will readily provide this information. As our technology uses nanoparticles, we can exploit certain size scale properties to improve the detection sensitivity of 'Light It Up'. In the presence of a magnet, iron nanoparticles are magnetic. Hence, if the nanoparticles are not bound to a biological fluid they can be simply removed using a magnet. With non-bound particles of 'Light It Up' removed, the bound particles will show up much more readily. We also aim to develop a solution of 'Light It Up' which will detect DNA directly in situ. It's the DNA that forensic scientists are really looking for when they search for biological fluids (although they also want information on the type of body fluid to help the police in their investigations). Finally, we wish to determine whether we can use 'Light It Up' to provide the police with information which can guide them in their investigations. For example, we want to establish whether we can detect explosive residues in fingerprints left at a crime scene and, for drugs and drug metabolites, in both fingerprints and body fluids. Our antibody-nanoparticle technology will specifically bind to such targets giving a fluorescent signal enabling the Police to focus their search for people handling explosive materials or dealing and/or using drugs respectively. Such information would undoubtedly help point the police in the right direction for their investigations.