The development of a new modified graphite pencil electrode for quantitative detection of Gibberellic acid (GA3) herbal hormone

Abstract In this practical work, an electrochemical sensor based on 5-ethyl 5-phenyl barbituric acid (EPBA) on Polyvinylpyrrolidone (PVP) modified pencil graphite (PG) electrode was fabricated for the quantification of Gibberellic acid (GA3). At the beginning, PG electrode was modified by a manual casting layer of PVP. Next, EPBA was placed on PVP/PG using the electrochemical deposition. EPBA/PVP modified PG electrode exhibited stable and strong electro catalytic effect with the archived parameters of ᾳ=0.62, logks=3.42 and Γ=8.82×10-8 mmolcm-2 for oxidation of GA3. Under the optimization electrochemical parameters, the calibration curve revealed a linear behavior over the concentration range of 15 to 225 nmolL-1 with the limit of detection 4.97 nmolL-1. EPBA acted as an electron-exchange for an enhancing charge transfer at the electrode interface and exploring the selective and sensitive response to GA3. This new developed sensor could practically measure GA3 in wheat and rice samples without serious interference from commonly interfering compounds. Therefore, we recommend EPBA/PVP/PGE sensor as an electrochemical device for determination of GA3 in real samples with convincing analytical results.