A New Sensor Electrode for Caffeine Determination Using Square Wave Voltammetry: Cytosine Modified Glassy Carbon Electrode

Korkmaz, Şeyma; Alovset Rustemova, Aysel; Aliyeva, Shabnam Jamaladdin; Sharifi, Hafizullah; Mülazımoğlu, İbrahim Ender; Demir Mülazımoğlu, Ayşen

doi:10.22034/abec.2024.719413

A New Sensor Electrode for Caffeine Determination Using Square Wave Voltammetry: Cytosine Modified Glassy Carbon Electrode

Document Type : Original Article

Authors

Şeyma Korkmaz ¹

Aysel Alovset Rustemova ¹^{, 2}

Shabnam Jamaladdin Aliyeva ¹^{, 2}

Hafizullah Sharifi ¹

İbrahim Ender Mülazımoğlu ³

Ayşen Demir Mülazımoğlu ³

¹ Necmettin Erbakan University, Institute of Science, Chemistry Department, Konya, Turkey

² Azerbaijan State Agricultural University, Azerbaijan

³ Necmettin Erbakan University, Ahmet Keleşoğlu Education Faculty, Chemistry Department, Konya, Turkey

10.22034/abec.2024.719413

Abstract

In this study, cytosine (CT) modified glassy carbon (GC) electrode was used to investigate the detectability of caffeine (CAF) found in foods such as tea, coffee and soft drinks. Using the cyclic voltammetry (CV) technique, 1 mM CT was prepared in pH 7.2 phosphate buffer solution (PBS) and modified at a scanning rate of 100 mV s^-¹ in the potential range of 1.0 V to 2.1 V. CT/GC electrode was characterized by CV, scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS) techniques. 1 mM CAF solutions were prepared in different supporting electrolytes such as H₂SO₄, HCl, HNO₃, and CH₃COOH within the potential range of +0.5 V to +1.7 V using square wave voltammetry (SWV) technique. Effect of the supporting electrolyte concentrations were investigated. CAF solutions in the concentration ranges of 0.75 to 0.05 mM and 0.025 to 0.0025 mM were prepared in 100 mM H₂SO₄ supporting electrolyte and calibration graphs were drawn. Line equations were created using the values read from the drawn graphs. Correlation coefficient (R²) values were calculated as 0.9947 and 0.9961, respectively. Using the calibration curves, limit of detection (LOD) and limit of quantification (LOQ) were found as 0.93 µM and 2.79 µM.

Keywords

Cytosine

Caffeine

Glassy Carbon Electrode

Cyclic Voltammetry

Square Wave Voltammetry

Subjects