Copper-neodymium coordination networks: An electrochemical approach for efficacious caffeine detection in beverages

Abstract

A novel copper neodymium octahedral shaped metal organic frameworks (Cu–Nd MOFs) was used to modify glassy carbon electrode (GCE) for caffeine (CAF) detection in commercial beverages (0.1–1.5 μM) with notable low detection limit (LOD) of 0.098 μM, and a limit of quantification (LOQ) of 0.327 μM. This enhanced sensitivity was attributed to the redox reaction of Cu (Cu²⁺ → Cu⁺) and Nd (Nd³⁺ → Nd²⁺) ions present within the framework structure. An exceptional reproducibility (RSD = 2.16 %), stability (RSD = 2.48 %), and selectivity of Cu–Nd MOFs/GCE towards CAF makes it as a promising electrochemical sensor material. Moreover, Cu–Nd MOFs has large electroactive surface area, superior mass transport, efficient ionic conductivity, synergistic effects, and chemical stability making it a potential material to be implemented in sensor devices to detect the minimal presence of CAF. Overall, Cu–Nd MOFs/GCE shows a significant potential for real-time applications for efficacious sensing of CAF in various food products.