Multifunctional Nanostructured Metal Selenides for Non-Enzymatic Electrochemical Sensors: Dopamine and Glucose Detection

Abstract

Glucose and dopamine (DA) play essential physiological functions associated with disorders such as diabetes mellitus, Parkinson's disease and schizophrenia. For both analytical applications and diagnostic testing, accurate glucose and DA determination is essential. In this current work, efforts have been made to develop non-enzymatic direct electrochemical sensors for DA and glucose based on transition metal chalcogenides as electrocatalysts . The bifunctional sensors capable of detecting glucose and DA levels simultaneously is highly desirable because diabetes often changes dopaminergic function and alters dopamine-regulated activity. Among all the niche applications and properties of transition metal chalcogenides, recently these materials have gained attention due to their favorable electrochemical properties owing to tunable redox behavior of the transition metal center. Recently we have identified several binary metal selenides and tellurides compositions grown on different flexible substrates through electrodeposition, hydrothermal synthesis as well as by chemical vapor deposition which exhibits exceptional activity for DA detection and electrocatalytic glucose oxidation at low applied potential. Typically, copper selenide nanostructures were synthesized which could detect glucose and dopamine with high selectivity at different applied potentials. These sensors also showed enhanced sensing parameters including low limit of detection and high sensitivity (0.068 µM and 26 µA µM-1 cm-2 respectively, for copper selenide catalyst) for glucose and dopamine, respectively. The electrochemical studies shows long-term stability as well as sensitivity with a detection region from 5 nm to 2 μM of dopamine, rapid response time along with excellent reproducibility. Furthermore, for practical application, human blood serum was also tested for accurate detection of DA and glucose level. The results suggested that such nanostructured metal chalcogenides-based sensor may be a potential candidate for designing continuous monitoring devices for detection of DA and glucose in physiological environments with blood and other tissue fluids. In this talk we will present detailed study of transition metal chalcogenides as electrocatalysts for dopamine sensing and direct glucose oxidation along with an understanding of their structure-property relationship.