Research from the University of Limerick has unlocked a major scientific challenge which has exciting potential for point of care medical tests. The research entitled ‘Nanoelectrical analysis of single molecules and atomic-scale materials at the solid/liquid interface’ is reported online in Nature Materials. Scientists have long been working to overcome barriers in the detection of minute levels of biomarkers in blood. Sensors that can rapidly and accurately assess a person’s health by detecting molecule-level traces of viruses and bacteria could save many lives by identifying the need for medical intervention at the earliest possible stage. These biomarker molecules elusive in blood so pinning them down and interrogating them with sensors is difficult. The solution proposed in the new research is to apply “liquid brakes” to molecules using silicone oil and place a one atom-thin insulating layer in between the molecules and the sensor surface. Dr Damien Thompson, Department of Physics and Energy, and Materials and Surface Science Institute (MSSI), UL explains; “The trick is to slow the molecule down and hold it at a safe distance from the sensor surface. You need to slide something in between the molecule and the surface and that something is a layer of alkanes.” You use alkanes every time you cook on your stove or fill up your car with fuel. In spite of their simplicity, alkanes have a hidden talent; they can screen electrical signals, allowing scientists to fingerprint molecules because the signal from the molecule is kept pure. The molecule’s energy levels are not contaminated by noise from the sensor surface. Dr Damien Thompson, added; “If we can measure molecules more accurately and quickly without the need for expensive laboratories then we can quickly diagnose conditions in patients. Imagine a situation where a life-threatening condition could be rapidly diagnosed in its incubation stage using a simple hand-held test outside of a lab environment. The potential is very exciting and this research has unlocked what has been a long-standing issue for the diagnostics community: how to place molecules near conducting surfaces without perturbing the molecule’s electrical properties. The potential is enormous, including identification of viruses causing Ebola, HIV and the common cold.” Dr Damien Thompson’s research is funded by Science Foundation Ireland as part of a Starting Investigators Research Grant and is enabled by high-performance computing facilities at the Irish Centre for High-End Computing (ICHEC). His work has produced design rules for how molecules with functions such as electrical switching and tumour targeting can be integrated into real devices.