Working Towards Ultrasensitive, Affordable Sensors for Glucose and Glyphosate

Their recent work results from an international collaboration with the University of Catania, the Institute for Microelectronics and Microsystems of the Italian National Research Council, the King Faisal University in Saudi Arabia and the University of Montréal in Canada.

They developed a new method to produce nanoporous gold particles on a transparent substrate. This method is based on the ultrafast laser processing of a nanoscale-thick gold-silver bilayer deposited on the substrate to induce the gold and silver melting, alloy and nanoparticle formation by a dewetting process. This is followed by the silver removal from the nanoparticles by an opportune chemical etching with the consequent rearrangement of gold in the form of nanoporous particles.

All the properties of nanostructures and nanomaterials are strongly dependent on their morphology. In this specific case, the surface enhanced Raman properties of the nanoporous gold particles are strongly determined, as suggested by the simulation work, by the particles’ morphology including porosity, pore size and gold ligament size. At each step of the fabrication process, microscopic analysis is fundamental to image the nanoparticles and to quantify the corresponding morphological characteristics. To this end, scanning electron microscopy was used.  

Dr. Ruffino is planning to expand on this result to fabricate some prototypes of ultrasensitive optical sensors, for example in glucose and glyphosate sensing.