Constructing an electrochemical sensor configuring as PGE/AgNPs/ Prednisolone for detection and determination of Caffeine in drug supplements and drinking samples

Background: In this research work, constructing and optimizing the applicability of a new electrochemical sensor based on modifying bare graphite pencil electrode with Ag Nano particles and prednisolone drug using cyclic voltammetry (CV) technique has been presented. Methods: The successive voltammogrames at low scan rates were applied on the surface of bare pencil graphite electrode to produce durable and stable films. Scanning electron microscopy was used to characterize the modified surfaces of PGE/AgNPs and PGE/AgNPs/ Prednisolone. The new electrochemical sensor was successfully utilized to estimate caffeine contents in pretreated drug supplements and drinking samples. Results: The results revealed that this modified electrode has a good electro catalytic activity to oxidation of caffeine with obtained parameters of α = 0.65, log Ks =3.39 and Γ =3.4×10-4. Under the optimized conditions, Caffeine was determined over the concentration of 25-600 nmoLL-1 with limit of detection of 8.17 nmoLL-1. Conclusion: This study focused on constructing and optimizing a new modified pencil graphite electrode to determine caffeine in its real samples. The simple, fast and cost effective electrodeposition technique was used to deposit AgNPs and Prednisolone. This electrochemical sensor also has some advantages such as high stability, desirable repeatability and acceptable sensitivity. So, this new sensor can be recommended for analyzing drug supplements and soft drinking samples with high accuracy and precision in analysis.