AUTHOR=Aflatoonian Mohammad Reza , Tajik Somayeh , Aflatoonian Behnaz , Beitollahi Hadi , Zhang Kaiqiang , Le Quyet Van , Cha Joo Hwan , Jang Ho Won , Shokouhimehr Mohammadreza , Peng Wanxi TITLE=A Screen-Printed Electrode Modified With Graphene/Co3O4 Nanocomposite for Electrochemical Detection of Tramadol JOURNAL=Frontiers in Chemistry VOLUME=Volume 8 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.562308 DOI=10.3389/fchem.2020.562308 ISSN=2296-2646 ABSTRACT=In this paper, graphene-based cobalt nanocomposite was synthesized and utilized for the development of a novel electrochemical sensor to detect tramadol. Tramadol determination was examined by cyclic voltammetry, differential pulse voltammetry, and chronoamperometry at graphene/Co3O4 nanocomposite-modified screen-printed electrode (G/Co3O4/SPE) in phosphate-buffered saline. Under the optimized condition, the detection limit of tramadol is 0.03 μM (S/N=3) in the linear ranges of 0.1–500.0 μM. Furtheremore, G/Co3O4/SPE was satisfactorily utilized to detect the spiked tramadol in tramadol tablet and urine specimens.