Biosensing with single molecule sensitivity based on photonic crystal membranes

This application relates to a 6 months visit to Stanford University, which is a part of my, Jon Olav Grepstad, doctoral work. My supervisors are Johannes Skaar at NTNU, Aasmund Sudbø at the University of Oslo, Ib-Rune at SINTEF and Olav Solgaard at Stanfo rd University. In my doctoral work, I have made a proof-of-principle sensor that demonstrates a novel method to detect single nano-particles. The current work has been published in a high-rank scientific journal, and at multiple international conferences and national workshops. I also got the chance to present my project as one of three finalists at the finishing seminar of NANOMAT 2011. The ultimate goal in my PhD is to make an advanced point-of-care diagnostic tool, which can analyze small human sampl es, typically a finger-prick sample of blood, to find relevant molecules that expose a patient's disease without having to use expensive and time-consuming techniques found in laboratories todays. Moreover, the aim is to substantially improve the sensitiv ity relative to current technologies, meaning diseases can be detected at an earlier stage than they can today. Generally speaking, there are multiple technical challenges in this project, involving micro-fluidics to make a compact and fast working syst em, and advanced surface chemistry to capture relevant biological molecules with localized selectivity. My doctoral work focuses on the transducer in the sensor, which involves the optical challenges related to how nano-particles can be detected when they have been immobilized at desired locations. The current sensor has detected particles down to ~50 nm in radius. Since relevant molecules typically are in the 5 nm range, the detection limit must be improved by a factor 10. This is what I hope to achiev e in collaboration with Olav Solgaard's research group during my visiting at Stanford.