Photochemical synthesis of polymer-stabilized silver nanoparticles for epinephrine sensing: Electrochemical, EG-FET and microcontroller based approaches

Epinephrine, a key catecholamine, regulates the sympathetic nervous system and plays a vital role in various physiological processes. This study presents various sensor applications for epinephrine detection, based on a polymer-stabilized silver nanoparticle composite catalyst, synthesized through a UV-mediated route. The metal-polymer composite system was characterized by transmission electron microscopy, X-ray diffraction, Raman and X-ray photoelectron spectroscopy techniques. The electrochemical redox behavior of epinephrine in the presence of the catalyst was studied using various voltametric and amperometric techniques. The electrocatalyst demonstrated high selectivity towards epinephrine detection in the presence of common biological interfering analytes like dopamine, uric acid and ascorbic acid. A sensing technique based on an extended gate field-effect transistor (EG-FET) was applied for epinephrine detection, achieving a limit of detection of 0.72 μM and a sensitivity of 0.049 μA.μM⁻¹.cm⁻². A microcontroller-based portable sensor was developed using an Arduino Uno R4 Wi-Fi module, enabling real-time monitoring and remote data transmission. The sensitivity and selectivity of the sensor make it a promising tool for on-site epinephrine detection in clinical and research applications.