Ultrasensitive quercetin electrochemical sensor based on reduced graphene oxide/β-cyclodextrin/graphene quantum dots/molybdenum trioxide composites

Quercetin is one of the flavonoids with antioxidant activity and has attracted great interest. Accurately and rapidly detection of quercetin belongs is of great significance. Herein, an ultrasensitive electrochemical quercetin sensor based on reduced graphene oxide/β-cyclodextrin/graphene quantum dots/molybdenum trioxide (rGO-β-CD/GQDs/MoO3) was constructed. The rGO-β-CD/GQDs/MoO3 presented excellent electrochemical detection for quercetin benefit from the excellent conductivity and adsorption enrichment effect of rGO-β-CD, good dispersion and stability of GQDs and electrocatalytic activity of MoO3. Under optimal conditions for the detection of quercetin, the rGO-β-CD/GQDs/MoO3/GCE showed wider linear range (5–2600 nM) and lower detection limit (LOD, 1.5 nM, (S/N = 3)). Furthermore, the sensor we constructed shows good accuracy and stability for the detection of quercetin in actual sample detections.