Project Lead(s): Michael Serpe
Reliable disease detection is important to prevent unnecessary deaths and is also important to prevent overtreatment of disease.
But in developing countries, patients presenting clinical signs of a specific illness are treated with no laboratory results for confirmation, leading to overtreatment due to misdiagnosis.
The project aimed to show that optical devices could be used as sensors for biomolecules that are indicative of diseases.
Optical devices were fabricated by sandwiching a ‘monolithic’ layer of microgels between two semitransparent Au (gold) layers.
These devices – referred to as etalons – exhibit characteristic multi-peak reflectance spectra, and the position of the peaks in the spectra primarily depend on the distance between the gold surfaces mediated by the microgel layer thickness.
The project team managed to optimize different components that are necessary to develop a working prototype of a multiplex point-of-care device.
They were able to spectroscopically determine the concentration of protein and DNA in solutions.
The team also showed that the positively charged microgel layer can collapse in the presence of negatively charged, single-stranded DNA (ssDNA) due to ssDNA-induced microgel crosslinking.
This collapse results in a change in the etalon’s optical properties, which can be used to detect target DNA in a complex mixture.
However, the team did not manage to develop the proposed device.
The team will be collaborating with others at the University of Alberta to introduce amplification mechanisms into the technology, such that visual colours can be correlated with DNA/protein concentration.