COF-Zincon dual signal amplification: A sensitive real-time electrochemical sensor for Zn²⁺ detection towards anxiety...

In recent years, abnormal total zinc levels in serum have emerged as a robust indicator of anxiety disorder. However, measuring total zinc level requires sophisticated instrumentation and specialized personnel. Therefore, if the specific association between Zn²⁺ in serum and anxiety disorder can be elucidated, it is promising to develop rapid and convenient diagnostic methods for anxiety disorder. In the field of Zn²⁺ detection, Electrochemical detection has been investigated as a means to quantify Zn²⁺ with precision, rapidity and cost-effectiveness. Nevertheless, most current electrochemical systems lack specificity.

In this study, the relationship between anxiety disorder and serum Zn²⁺ level was first elucidated, with research finding indicating that anxiety in mice correlated with a marked decline in serum Zn²⁺ level. Subsequently, a sensitive and specific electrochemical sensor was developed to detect Zn²⁺ with outstanding detection performance for the diagnosis of anxiety disorder. In this sensor, covalent organic framework material (COF_Tp-Th) was utilized to load a substantial amount of gold nanoparticles (AuNPs) via Au-N bonds to obtain COF_Tp-Th-AuNPs material. AuNPs can enhance electrode catalysis and conductivity and served as a platform for subsequent material integration. Furthermore, a large quantity of Zincon reagent for specific recognition and detection of Zn²⁺ was loaded onto the AuNPs through Au-S and Au-N bonds to improve electrode specificity, resulting in the construction of the target electrode modified material of COF_Tp-Th-AuNPs-Zincon.

Long-range ordered COF_Tp-Th can adsorb Zn²⁺ through its rich tetradentate coordination ONNO chelation sites formed by Tp and Th, representing the primary signal amplification. Simultaneously, the abundant Zincon in COF_Tp-Th-AuNPs-Zincon material with high affinity for the specific recognition and detection of Zn²⁺ contributed to secondary signal amplification. This approach leads to a significant improvement in the detection performance of Zn²⁺ and holds promise for providing robust support for the diagnosis and monitoring of anxiety disorder.