Project Lead(s): Alexandre Brolo
Dengue fever is a tropical disease transmitted by the female of the Aedes Aegypti mosquito, which infects between 50 to 500 million people every year.
Since the early symptoms of the disease are similar to a common flu, a quick diagnostic method is required for rapid identification and immediate treatment implementation.
The goal of this project was to develop a low-cost plastic strip sensor capable of detecting dengue colourimetrically from the saliva of infected individuals.
The principle of operation of the dengue sensor is based on surface plasmon resonance from metallic nanostructures. Surface plasmons are surface waves generated by the excitation of free electrons in a metal by an optical field. The characteristics of these surface waves can be altered by the adsorption of species at the surface of the nanostructures
In another words, the colour of the device changes when certain molecules are adsorbed at the sensor surface.
Two types of dengue-related proteins were targeted in this project: NS1 protein, which is part of the structure of the virus capsid, and the dengue immunoglobulin M (IgM) protein.
A significant amount of optimization was carried out to determine the proper surface TBA DengueAg Saliva test.
The fabrication method developed can be scaled up and is on track to reach the target cost of less than $1 per strip.
The optical measurement system was also implemented.
Testing of the strips was realized in several steps, culminating with applications to real samples from infected patients.
Although the final result was not totally successful, the project team has a clear sense of what needs to be improved.
Knowledge of this project has been disseminated in conferences.