Nanotechnology has come to paper. Although the special paper is made from cellulose, like regular paper, the cellulose fibers are on a nanoscale, which gives it lower surface roughness and much higher transparency than traditional paper.
Several applications are being investigated for nanopaper, including their use as filters, wound dressings, sponges that soak up oil pollution, and now as a range of low-cost sensors, thanks to nanosilver particles imbedded in the paper.
“To date, bacterial nanopaper has been scarcely explored for optical (bio)sensing applications,” said Arben Merkoçi, ICREA Research Professor and director of the Nanobioelectronics & Biosensors Group at Institut Català de Nanociencia i Nanotecnologia in Barcelona, Spain. “Hence, we sought to design, fabricate, and test simple, disposable and versatile sensing platforms based on this material,” he stated in the online journal Nanowerk.
Sensors shaped from nanopaper, and imbedded with silver nanoparticles, produce small electrical currents when hit by light. By ‘fine tuning’ the amount of silver nanoparticles, and adding different chemicals to the paper, the researchers could measure the electricity produced and delineate among various kinds of colors which might indicate types of bacteria, blood diseases and other medical anomalies usually detected by more expensive sensors.
Another advantage of the nanopaper sensors is that they can easily be produced in various shapes depending upon their application.
Researchers Eden Morales-Narváez and Hamed Golmohammadi noted: “We expect that these novel platforms will pave the way to new optical (bio)sensors or theranostic [diagnostic tests directly linked to the application of specific therapies] devices that are simple, transparent, flexible, disposable, lightweight, miniaturized and perhaps wearable.”