Poly(riboflavin)/NaOH/graphene nanoplatelets modified graphite composite paste electrode for the determination of antioxidant rutin

Instead of going for complicated and toxic materials (mercury electrodes), we have chosen riboflavin (RF), graphite, and graphene nanoplatelets (15 mg) because these are eco-friendly and efficient materials for the fabrication of electrochemical sensors. The electrochemically prepared poly(riboflavin)/NaOH/graphene-nanoplatelets modified graphite paste electrode (PRFGMGPE) and graphite paste electrode (GPE) properties before and after modification are confirmed by field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectroscopy (EIS). PRFGMGPE produces upsurge electrochemical reactions with quasi reversibility, but graphene-nanoplatelets modified graphite paste electrode (GMGPE), poly(riboflavin)/NaOH modified graphite paste electrode (PRFMGPE), riboflavin/NaOH/adsorbed/graphene-nanoplatelets modified graphite paste electrode (RFAGMGPE) and GPE shows the low binding capability and current response for rutin (RU). Under calibrated circumstances, PRFGMGPE detects RU in the range from 0.1 to 1.4 µM with an impressive lower detection limit (LOD) of 4.84 × 10⁻⁹ M using differential pulse voltammetry (DPV). The performance of PRFGMGPE towards RU recognition demonstrates fine binding selectivity and anti-interference features in presence of different organic molecules and metal ions. The real-time RU testing is performed in green tea and blood serum samples with agreeable recoveries by reducing the matrix effect. Moreover, simultaneous interference was also performed with co-existing molecule hydroquinone (HQ) using the DPV technique. Graphical abstract: [Figure not available: see fulltext.]