“The main innovation of this work lies in two areas: first, we use plasmonic nanostructures as a new class of sensing elements to greatly expand the library of targets that can be analysed on a conventional chemical sensor array (28,46,47,48); and second, we have integrated a portable smartphone reader to facilitate field deployment and implementation.”
“In addition, the cost of the chemical sensor array is estimated to be about 15 cents per test and the smartphone attachment is about US$20 (excluding the phone), which is orders of magnitude less expensive than commercial e-nose sensors.”
Dr. Zheng Li (Department of Chemical and Biomolecular Engineering, NC State University) and other collaborators have created a portable, cheap platform that can detect and identify volatile organic compounds that are emanated when a plant leaf is under attack by a type of blight, allowing a quick and cheap way to measure plant health. They accomplish this by creating a sensor array combining “plasmonic nanocolorants” – gold nanoparticles of specific shape and size – and organic dyes which fits into a 3D printed smartphone case. The image below was collected using the JEOL 2000FX with an acceleration voltage of 200 kV.