Redefining hormonal diagnostics
✔ highly specific
✔ usable outside the lab
✔ applicable to various hormones
For the current detection of melatonin, laboratories use ELISA, HPLC or mass spectrometry.
These methods are standard scientific approaches but they are not specifically designed for melatonin. Mass spectrometry, for example, is highly sensitive but very expensive and not every laboratory can work with it.
Also, the suitable method depends on the sample fluid used to measure the melatonin production of a patient. There is blood, urine, and saliva.
ELISA is an established method to measure melatonin metabolites in urine, but it is less specific with blood and saliva. The negative aspect of urine is its imprecision since the hormone itself is not measured. In contrast, HPCL is the go-to method for high levels of melatonin in blood. Unfortunately, these high levels occur rarely.
In comparison with the other fluids, saliva is suited best, as it linearly contains about 30% of the melatonin concentration in blood. Using saliva instead of blood is better for the patients as it is a non-invasive sample-taking.
This is the reason why we decided to utilize saliva as a sample for our biosensor.
Our biosensor is specifically designed for melatonin. No other molecules that occur in saliva bind to our modified receptor. Thus, Melasense has a higher sensitivity than current methods. Moreover, as RZR is about 53 kDa, it affects the shift in light of LSPR a lot. Such a change is easily measurable.
By advancing our sensor to become a cell-free device, we are no longer bound to neither S1 lab safety nor laboratory equipment. Samples can be measured outside the lab directly in the doctor's office.
As a result, it offers a point-of-care-diagnostic and more data can be collected for future studies.
We use the DNA-binding sequence ERE linked to the wafer. There are alternative sequences that bind nuclear receptors for other hormones, such as estrogen and cholesterol.
Both the DNA-binding sequence and the corresponding receptor could be easily exchanged by using a different chip. This offers the opportunity to use our hardware device for the measurement of other hormone levels.
Furthermore, to use our method, doctors and laboratories will only have to buy the device once and after that just change a small chip at the end of every measurement.
This allows us to offer our hardware to a much more economical prize in comparison with the common methods that have to be bought again and again.
Finally, we have engineered an innovative measuring method in the spirit of iGEM:
We were able to mend the relatively new physical phenomenon of LSPR with the age-old biological phenomenon of transcription factors.