Efficient “on–off” photo-electrochemical sensing platform based on titanium dioxide nanotube arrays decorated with silver doped tin oxide for ultra-sensitive quercetin detection

[Display omitted] •An enhanced photo-electrochemical sensor with excellent selectivity was developed.•The Ag@SnO2/TiO2 NTs illustrated excellent photo-electrochemical activity.•Ag@SnO2/TiO2 NTs exhibited ultra-high sensitivity with a low limit of detection.•Successful quantitative analysis was the main advantage of this sensitive method. Quercetin, a bioflavonoid found in fruits and vegetables, is a potential anticancer compound with strong anticancer activity. Hence, a photo-electrochemical sensor was developed for the detection of quercetin. In the present work, silver doped tin oxide (Ag@SnO2) was engineered via a solvothermal method, and titanium dioxide nanotubes (TiO2 NTs) were synthesized through anodizing process. A nanohybrid of Ag@SnO2 and TiO2 NTs was used as an electrode modifier to fabricate the photo-electrochemical sensor for the photo-electrochemical determination of quercetin. The Ag@SnO2 exhibited high electrocatalytic activity and good stability. TiO2 NTs have a high surface-to-volume ratio and superior conductivity. Due to the synergistic effect of the Ag@SnO2 and TiO2 NTs, the developed photo-electrochemical sensing platform was employed to quantitatively determine quercetin with high stability and sensitivity. The superior sensing performance of the proposed sensing platform was confirmed based on the low limit of detection of 1.2 nM which depicted two linear ranges from 0.004 to 0.124 and 0.124 to 3.6 µM for quercetin. The main advantage of this specific, sensitive, and, simple method with a short analysis time was in determining quercetin in honey, tea, and golden delicious samples.