Electrochemical and density functional simulation studies of a cobalt(ii) imidazolate framework for the real-time sensing of atrazine

Abstract

Atrazine, a human-made herbicide, is infamous for its endocrine-disrupting properties, with adverse consequences on the immune, reproductive, and nervous systems. Consequently, effective recognition of atrazine in various environments, such as water, is critically important. This work presents a precise and efficient method for detecting atrazine across various environments, utilizing a well-established electrochemical technique. A metal organic framework (MOF) ZIF-67 has been synthesized and employed as a catalyst for the electrochemical detection of the triazine herbicide atrazine. Structural, morphological, and chemical analyses were conducted to evaluate the sensing material and to elucidate the interactions between the sensor and the analyte. The ZIF-67 was then integrated on the surface of the working electrode (carbon paste electrode (CPE)) to form a ZIF-67 modified-CPE (ZIF-67/MCPE). The ZIF-67/MCPE was utilized to detect atrazine by electrochemical techniques including differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The sensor demonstrated excellent sensitivity and was effective in detecting atrazine. The modified sensor demonstrated a lower limit of detection (LLOD) of 3.7 μM within a linear concentration range of 4–44 μM and exhibited a strong linear correlation efficiency of 0.97. Computational results corroborated the experimental findings, revealing that the combination of ZIF-67 with atrazine forms minor triangular structures and exhibits enhanced dynamics compared to the pristine MOF. This improvement in the crystallinity of the ZIF-67 MOF with atrazine is attributed to the negative binding energy and reduced energy gap at the interface between the MOF and atrazine. Additionally, the sensor's practical application was evaluated by testing it on sewage water and fresh liquid milk. The sensor demonstrated an exceptional ability to detect atrazine, with a recovery rate ranging from 96% to 99%. This approach holds promise for developing electrochemical or solid-state devices for real-time atrazine monitoring.