Amperometric determination of sulfide based on its electrocatalytic oxidation at a pencil graphite electrode modified with quercetin

► A new method for electrocatalytic determination of sulfide was proposed by using a PGE/QH2. ► Quercetin was firstly used as redox mediator for electrocatalytic oxidation of sulfide. ► PGE/QH2 exhibits disposable electrode fabrication with low costs and easy fabrication. ► The proposed method was successfully applied to the determination of sulfide in waste waters.