Articolo in rivista, 2015, ENG, 10.1007/978-3-319-09617-9_26

Determination of caffeine @ gold nanoparticles modified gold (Au) electrode: A preliminary study

Trani A.; Petrucci R.; Marrosu G.; Curulli A.

ISMN CNR Istituto per lo Studio dei Materiali Nanostrutturati Consiglio Nazionale delle Ricerche, Via del Castro Laurenziano 7, Roma, 00161, Italy; Sapienza Università di Roma, Via del Castro Laurenziano 7, Roma, 00161, Italy

Caffeine is a natural alkaloid exerting many physiological effects, such as stimulation of the central nervous system, diuresis and gastric acid secretion. It is widely distributed in plant products and beverages and its quantification is mainly of pharmaceutical and alimentary concern. In this paper, we describe an electrochemical study based on the modification of a gold electrode (Au) surface by deposition of functionalized gold nanoparticles by Cyclic Voltammetry (CV). The oxidation system is characterized by an anodic peak in the positive-going step and by the absence of any cathodic peak on the reverse scan, indicating that the oxidation is irreversible. At the modified electrode, the voltammetric peak height increases vs. that @ the bare one, depending on the nanoparticles functionalization. The best performances were observed @ Au electrode modified with colloidal gold nanoparticles (AuNPs) stabilized into a chitosan matrix. In order to optimize the influence of different electrolytes on the sensor response, different electrolytic solutions (nitric acid, sulfuric acid, phosphoric acid and hydrochloric acid) were used. The electro-chemical behavior of caffeine was also studied in aprotic medium with the aim to clear up the different mechanisms the oxidative process occurs through in aqueous and in aprotic medium.

Lecture notes in electrical engineering (Print) 319 , pp. 147–151

Keywords

nodic oxidation; Caffeine; Cyclic voltammetry; Electrochemical electrodes; Electrodes; Fiber optic sensors; Hydrochloric acid; Metal nanoparticles

CNR authors

Trani Alessandro, Curulli Antonella

CNR institutes

ISMN – Istituto per lo studio dei materiali nanostrutturati