Fe-MIL-88A hexagonal rods as peroxidase mimetic at neutral pH for one-pot glucose colorimetric assay

Abstract

• Rod-like Fe-MIL-88A was prepared via a simple hydrothermal method. • The Fe-MIL-88A possessed peroxidase-like properties under neutral conditions. • A one-pot colorimetric method for glucose detection was developed based on the Fe-MIL-88A as a peroxidase mimic. • The proposed method with high selectivity and acceptable reproducibility was accurate, reliable and applicable. In consideration of the promising application of peroxidase (POD)-like nanozymes in biomedical analysis, the development of POD mimics with good catalytic performance under neutral conditions remains significant. As a new catalyst, metal-organic frameworks have been explored as candidate nanozymes owing to their high catalytic activity, good stability, flexible and simple synthesis methods, diverse types, and properties. Herein, rod-like Fe-MIL-88A was successfully synthesized via a simple hydrothermal method. Fe-MIL-88A exhibited POD-like properties under neutral conditions and a stronger affinity for substrate 3,3 ' ,5,5 ' -tetramethylbenzidine and H 2 O 2 than natural horseradish POD. This result was primarily due to the additional exposed (100) facets of rod-like Fe-MIL-88A, which can catalyze the decomposition of H 2 O 2 to •OH more easily. Based on the POD-like properties of Fe-MIL-88A under neutral conditions, combined with glucose oxidase, a one-pot colorimetric analysis method for glucose detection was established. The proposed measurement had a linear range of 1–100 µM and a limit of detection of 0.45 µM. The colorimetric method was accurate, reliable, highly selective, convenient, and time-saving. Furthermore, the one-pot method was successfully applied to detect the concentration of glucose in human blood samples, and the measured results were consistent with those of commercial glucose meters, indicating that the proposed method can be a potential candidate for glucose detection.