Localized surface plasmon resonance sensor
We had three requirements for our hardware sensor: sensetivity, cost effectiveness, quick processing.
In order to get a fast result we decided that our sensing solution needed to be cell-free, because living genetically modified organism (GMOs) in the European Union are only allowed inside S1 laboratories. The main problem with the measurement of melatonin in clinical use today is that the probes need to be sent to specialized laboratories. Here at University Hospital Aachen one of the largest hospitals in Europe, the probes for melatonin are sent 100 km away to a lab in Moenchengladbach. This is both from a time perspective but also from a cost perspective not feasible.
At first the idea was to built a photometer that could detect flourescence. Though this tool is quite versatile, there are many open source devices out there with good performance. The iGEM Teams Munich 2017, Aberdeen 2014 and Aachen 2014 for example built photometers.
Discussing our hardware project with one of our advisors, Prof. Dr. Wiechert, he brought up Surface Plasmon Resonance sensing as one of the most sensetive methods out there. It turned out to be our solution to an easily operated, cost-efficient and quick Sensor with a high specificity.
There are two parts of our hardware device, the spectrometer and the LSPR. The spectrometer is described separately because it is the tool to measure the LSPR, hence it can be used for every other optical application.