Iridium(III) complex functionalized ZIF-8 as a novel POD-like nanozyme for visual assay of triazine pesticides

Due to the unique advantages of mimicking natural enzymes, nanozymes have received ever-growing interest in a wide range of fields including analytical chemistry in the past two decades. Exploring novel kinds of nanozymes with efficient active sites has always been one of the most important and hot topics in nanozyme-related research so far, especially in portable monitors. Herein, zeolitic imidazolate framework-8 (ZIF-8) incorporated with an organometallic iridium(III) complex as a new active site denoted as Irppy-ZIF-8 obtained via a one-pot coordination reaction between the iridium solvent complex and 2-methylimidazole is reported as an efficient peroxidase (POD)-like nanozyme. Importantly, due to the specific inhibition effects of triazine pesticides on the POD-like activities of this novel nanozyme, a portable acetylcholinesterase (AChE)-free colorimetric sensor via a smartphone apart from a UV-vis spectrometer to detect triazine pesticides in real vegetable sample analysis is further successfully proposed in this work. It should be noted that this work could not only open up a new avenue to explore novel kinds of nanozymes from organometallic complexes as active sites, but also promote the progress in emerging applications of nanozymes in visual and portable sensors in the future.