Anodic and cathodic dual-mode cysteine detection utilizing a glassy carbon electrode co-activated by electrochemical pretreatment and fully fluorinated cobalt phthalocyanine

Abstract

l-cysteine (Cys), a fundamental amino acid within the human body, is crucial for a variety of biological processes. Its concentration levels offer valuable insights into an individual’s health status and are instrumental in the early diagnosis of various conditions. Traditional electrochemical detection techniques for Cys, primarily based on anodic oxidation, require complex and time-consuming steps including the creation of electrocatalysts and subsequent electrode modifications. This method is also prone to inaccuracies due to interference from other easily oxidized electroactive substances. To address these challenges, we present an innovative dual-mode detection strategy for Cys, leveraging both anodic and cathodic responses on a glassy carbon electrode. This electrode is dual-activated by electrochemical pretreatment and fully fluorinated cobalt phthalocyanine, facilitating a robust and reversible transformation between cystine and Cys. Remarkably, this method enables Cys detection at negative potential range, significantly reducing interference from prevalent biological and electroactive compounds like ascorbic acid and uric acid. Moreover, the process for modifying the electrode is remarkably simple, efficient, and eco-friendly.