Leuven, Belgium: Researchers at the nanotechnology research centre Imec have demonstrated biosensors based on nanostructure geometries that increase their sensitivity and allow the detection of extremely low concentrations of specific disease markers.
This development paves the way for early diagnostics of cancer by detecting low densities of cancer markers in human blood samples. Functionalized nanoparticles also may be able to help treat cancer and other illnesses by binding to diseased cells and destroying them.
Imec aims to develop biosensor systems exploiting a phenomenon known as localized surface plasmon resonance in noble metal (e.g., gold and silver) nanostructures. The biosensors are based on the optical detection of a change in the spectral response of the nanostructures upon binding a disease marker. Changing the morphology and size of the noble metal nanostructures can increase the detection sensitivity.
The biosensor system is cheap and easily extendable to multiparameter biosensing. Imec currently has broken symmetry gold nanostructures that combine nanorings with nanodiscs. Combining different nanostructures in close proximity allows the detailed engineering of the plasmon resonance of the nanostructures.
More specifically, Imec targeted an optimization of both the width of the resonance peak and the resonance shift upon binding of the disease marker. With respect to these parameters, the new geometries clearly outperform the traditional nanospheres. Therefore, they are better suited for practical use in sensitive biosensor systems.
Collaborators in this work included the Catholic University of Leuven, Belgium, Imperial College of London, the U.K., and Rice University of Houston, Texas.