Fabrication of screen printed electrodes on biodegradable substrates (nanocellulose and onion films Allium cepa L.) for applications in the medical, food and agroindustrial industries

Abstract

Screen printed electrodes (SPEs) are the most successful devices in the sensor market. The best-known example is the glucose biosensor used in the modern diagnosis of Diabetes mellitus, which moves one billion dollars in the market. SPEs have desirable characteristics for a sensor, such as high sensitivity, accuracy, robustness and selectivity, as well as easy manipulation. Additionally, the SPEs can be manufactured with low-cost and in large scale, with possibility of miniaturization and complete automation of the production process. With unlimited modification possibilities, SPEs can be used to develop sensors and biosensors for a wide range of applications in the medical, industrial, environmental and safety fields. SPEs are highly consumed products in Brazil, being among the main markets the centers of R&D&I for develops analytical applications, and to a lesser extent, the automotive industry and the health sector. However, these devices are not produced in Brazil and are imported with high prices, which can vary between R $ 18.19 and 26.13 per disposable unit. Another important limitation is that these electrodes are currently manufactured on rigid substrates of ceramic origin, preventing the production of non-invasive biosensors required for current clinical analysis, or in flexible synthetic polymers such as polyethylene terephthalate (PET) and polyvinyl chloride (PVC) which are highly contaminating. All this scenario makes it difficult to transfer applications developed in laboratories to commercial products and popular use. Biopolymers have been considered the most viable alternative for the substitution of non-biodegradable synthetic polymers. Within these materials, the nanocellulose and onion films (Allium cepa L.) stand out for their extraordinary physical characteristics (eg. high mechanical stability, high crystallinity and flexibility). Nanocellulose has been successfully applied in medicine as temporary skin dressings, scaffolds, and controlled drug delivery systems due, among other factors, to its high biocompatibility and similarity with cutaneous collagen fibers. Recently, onion films have been exploited by the company BioSmart Nanotechnology in the manufacture of edible packaging for food and as materials for the manufacture of electronic devices. Based on the above, the present project aims at the development of SPEs in flexible substrates with high biocompatibility and biodegradable, based on the use of biopolymers such as Nanocelulose and onion film (Allium cepa L), as well as nanomaterials produced at BioSmart Nanotechnology to improve the analytical performance of the devices. The main commercial focus of these products are the Brazilian R&D&I centers, in addition, with the integration of the advantages of the SPEs and the biocompatibility of the biodegradable biopolymers chosen, other markets can be approached, such as the manufacture of smart-packaging, platforms for sensors and biosensors of interest in sports medicine and agroindustrial. (AU)