As part of King’s Forensics, the Forensic Biochemistry group headed by Dr Nunzianda Frascione investigates the nature and evidential use of forensic trace evidence such as biological fluids, touch DNA and fingermarks. Such traces are often the most important forms of evidence encountered within forensic casework and their presence may help support or refute victim, suspect or witness claims about events. The group works closely, both on a technical and operational level, with police forces, forensic providers, and government-associated laboratories on several research streams.
Determining the presence of biological fluid depositions may be considered paramount to many forensic investigations, with fluid detection and identification often elucidating the circumstance and severity of a criminal offence. Furthermore, successful fluid recovery can yield a highly valuable source of genetic material, which may in turn associate an individual with a specific place, object or event. However, unless immediately visible, ascertaining the location of a fluid deposit can be very challenging, with a meticulous visual examination by trained personnel presently being the most effective method of detection. Small or transparent fluid traces, particularly those deposited on dark backgrounds, may often be missed. Current presumptive tests are impaired by several well-characterised limitations. The demand is therefore apparent for new fluid detection strategies that would allow for the simultaneous localization and accurate identification of biological fluid deposits. Fluorescent biosensor technology shows exciting potential for the development of novel body-fluid identification methods that may enable the non-destructive detection and localization of biological evidence based on interaction with highly specific intra-fluidic targets. The research focuses on the fabrication of antibody-, aptamer-, peptide-based sensors, not only for biological fluids, but also for other forensically relevant targets and surfaces. This includes, for example, the design of a multiplex fluorescent biosensor for the specific, sensitive and real-time detection of nerve agents in situ, without the need for specialist equipment. The successfully developed platforms are also currently being investigated and adapted to allow the ‘stand-off’ visualization of SARS-CoV-2 deposits and the effective monitoring of surfaces potentially contaminated with viral particles.