Graphene Catalytic Growth on Copper for Glucose Sensing Applications

Abstract

Recently, carbon nanomaterials have become a hot topic within the field of materials science because they have the potential to provide solutions to technological and environmental challenges in various areas. Among these materials, graphene is rapidly emerging as one of the most exciting materials for electro catalysts in electrochemical applications such as super-capacitors, Li-ion batteries, solar cells, and biosensors, due to its unique structure and electronic properties. Applications of graphene in biology are very appealing due to the possibility to have a conductive substrate prone to be modified to strictly interact with specific molecules if properly functionalized [1].Although a basic energy source for humans, dysfunctions in the metabolism of glucose are becoming more and more common. These metabolic diseases are called diabetes. At the beginning of the new millennium, 172 million people were affected by diabetes and, according to estimation, that number would have risen to 366 million in 2030 [2]. However, this latter number has already been reached and new estimation for 2035 foresee 595 million cases [3], with diabetes becoming the 7th cause of death [4]. In this work, deposition of graphene on thin and flexible electroplated copper surface by chemicalvapor deposition (CVD) has been researched for bottom-up glucose sensor building. Copper samples covered with graphene have then been used as electrodesin glucose sensors and their performances have been compared with that of bare copper.CVD is one of the most promising fabrication methods of graphene; this method is probably the best candidate to be used in the electronic industry, due to the high-quality and low defects layers it can yield. Electrodeposited copper substrates have been used as catalysts for the atmospheric pressure CVD process. These substrates have been used as deposited, or further processed to tailor their surface properties: for example, the effect of annealing in a reducing atmosphere and electropolishing have been researched. Graphene/FLG surface was then decorated with gold nanoparticles via immersion plating, to enhance sensor sensitivity. Finally, inkjet printing of copper oxide nanoparticles was implemented to test the properties of the so obtained nanohybrid. To assess the quality of grown graphene layers, Raman spectroscopy was employed, due to well-known graphene/FLG Raman fingerprints. Further characterization with a scanning electron microscope (SEM) and with X-ray photoemission spectroscopy (XPS) and UV photoemission spectroscopy (UPS) has been performed. [1] Sharma, N., Ojha, H., Bharadwaj, A., Pathak, D.P., Sharma, R.K., 2015. RSC Adv. 5 (66), 53381–53403. [2] Wild, S., Roglic, G., Green, A., Sicree, R. & King, H. 2004, "Global Prevalence of Diabetes: Estimates for the year 2000 and projections for 2030 ", Diabetes care, vol.27, no. 5, pp. 1047-1053. [3] http://www.expo2015.orgmagazineitlifestylediabete–tutti-i-numeri-in-italia-e-nelmondo.html [4] Tian, K., Prestgard, M. & Tiwari, A. 2014, "A review of recent advances in non-enzymatic systems", vol. 41, pp. 100-118.