Cobalt Oxyhydroxide Nanoflakes/Cellulose Composite Membranes with Enhanced Detection of Ascorbic Acid

Compared with complex biochemical detection systems, the development of a simple test strip is of great significance for outdoor real-time detection and analysis. In this study, cobalt oxyhydroxide (CoOOH) nanoflakes were synthesized by a simple redox method and well dispersed in a high-purity cellulose matrix to obtain CoOOH nanoflakes/cellulose composite membranes (CCMs). The prepared CCM exhibits a competitive detection performance for ascorbic acid (AA) compared to a pure CoOOH nanoflake solution. The dispersion mechanism of CoOOH nanoflakes into cellulose was well analyzed and discussed with the help of various experiments and characterizations, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Additionally, the detection behavior of CCMs to AA was evaluated on a standard AA solution. The principle of AA detection is that CoOOH nanoflakes can react with a 3,3',5,5'-tetramethylbenzidine (TMB) solution to produce a blue color, but the color intensity can be inhibited in the presence of AA. Based on this, the detection behavior was deeply investigated including real samples and in the presence of other potential interferences also. This work provided a simple, low-cost, and fast platform for AA detection in the field of food safety.