An electrochemical sensor based on a ZrP/Cu-β-CD/MWCNTs composite for accurate epinephrine determination in serum with high recovery

Abstract

This paper presents a high-performance electrochemical sensor for the sensitive and selective detection of epinephrine (EP), fabricated by integrating zirconium phosphate (ZrP), Cu-β-cyclodextrin (Cu-β-CD), and multi-walled carbon nanotubes (MWCNTs) on a glassy carbon electrode (GCE). The morphology and structural properties of the composite were systematically characterized. The ZrP/Cu-β-CD/MWCNTs modified GCE exhibited exceptional electrochemical performance, attributed to the synergistic effect of its components. The ZrP/Cu-β-CD/MWCNTs-based sensor showed a wide linear detection range for EP, spanning 3–80 µM and 80–239 µM, with a low limit of detection (LOD) of 0.39 µM. Amperometric i–t measurements revealed excellent selectivity, enabling accurate EP determination even in the presence of common interfering substances. Moreover, the sensor showed good reproducibility and long-term stability over 25 days. In practical applications, the sensor was successfully applied to the detection of EP in human serum samples, achieving recovery rates ranging from 90.245% to 102.280%. These results highlight that the ZrP/Cu-β-CD/MWCNTs-based electrochemical sensor is a promising tool for potential clinical diagnosis and point-of-care testing of EP-related diseases.