Development of graphene-chitosan composite modified screen-printed carbon electrode and its application for detection of rutin

Graphene is a prospective material for sensing devices due to its excellent electronic, thermal, and mechanical properties. In this study, low oxygen graphene was synthesized from graphite and nitronium ion using a microwave-assisted method. Graphene was dispersed into 0.05% chitosan solution and deposited by drop casting method on to screen-printed carbon electrode (SPCE) to form graphene-chitosan composite modified SPCE (SPCE-G-chit). The electrochemical performance of SPCE-G-chit was evaluated using flavonoid 3',4',5,7-tetrahydroxyflavone-3β-D-rutinoside (rutin). SPCE-G-chit provides linearity with R² of 0.9944 for rutin measurement in the concentration range of 5× 10⁻⁷ to 1× 10⁻⁵ M. Meanwhile, the linearity of rutin at SPCE was lower (R² 0.9396). Limit of detection (LOD) and limit of quantitation (LOQ) of rutin measurement at SPCE-G-chit was lower (0.23 µM and 0.58 µM, respectively) compare to SPCE (LOD = 0.69 µM and LOQ = 1.75 µM, consecutively). The accuracy of rutin measurement at SPCE-G-chit was 99.45% while the accuracy of rutin measurement at SPCE was 72.18%. The result indicated that SPCE-G-chit provides superior analytical performance than SPCE and potential for electrochemical sensor development.