Igem Aachen

We are iGEM Aachen and are facing a medical issue that has not been given proper importance in the past: melatonin. Melatonin is a small molecule produced in the pineal gland. Melatonin is mostly known as a sleeping hormone in mammals, but as the scientific research of the past decade shows, melatonin regulates all aspects of human physiology and malfunctions in the production of the hormone is correlated with numerous diseases. Malfunction of the melatonin production is primarily associated with sleeping disorders. But studies found out that melatonin also plays an important role in neurodegenerative diseases (Alzheimer’s and Parkinson‘s disease), psychological disorders (depression, schizophrenia) and fibromyalgia. Melatonin also acts antiproliferative on inflammation and reduces reactive oxygen species, which allows cells to live longer. Currently, melatonin is measured with the ELISA assay, which uses antibodies. This method are very expensive, making the melatonin measurement a costly diagnostic method. Our vision is to create a quick, cheap and non-invasive diagnostic method for the measurement of melatonin. The biological component of the biosensor will be a genetically modified yeast cell. By implementing a mammalian melatonin-sensitive receptor into the cell we are able to measure the melatonin concentration. Since living cells require maintenance, our ultimate goal is a cell-free solution that is easy to use. This novel cell-free approach will use a highly sensitive method called localized surface plasmon resonance (LSPR). A bond of a melatonin-sensitive protein to a DNA sequence that is immobilized onto a nanoparticle surface, effects the refractive index. Smallest differences in the refractive index can be detected through a change in the optical absorption. Since the change in the optical absorption occurs at visible wavelengths, we can use a regular smart phone camera as a sensor.