Self-sacrificial template synthesis of mixed-valence-state cobalt nanomaterials with high catalytic activities for colorimetric detection of glutathione

Abstract

Mixed-valence-state cobalt (MVSC) nanomaterials have attracted tremendous interest because of their extraordinarily high electron mobilities and catalytic activities. The design and synthesis of highly active MVSC nanomaterials with appropriate Co2+/Co3+ ratios are extremely desirable. In this work, MVSC nanomaterials with high surface areas and uniform size distributions were fabricated using a self-sacrificial template strategy. The MVSC nanomaterial with the optimum Co2+/Co3+ ratio showed excellent catalytic activity in the oxidation of 3,3′,5,5′-tetramethylbenzidine than other types of nanostructured Co3O4, e.g., nanoplates, nanorods, and nanocubes. Based on the catalytic activity of the MVSC nanomaterial, a simple and sensitive colorimetric sensor of glutathione (GSH) was developed due to the antioxidant ability of GSH. The linear range was 0.5–40μM, and the limit of detection was 0.03μM. The proposed sensor was used to determine GSH in eye drops and health care products. The recoveries ranged from 97.3% to 104.0%, indicating that the proposed colorimetric sensor for GSH quantification is reliable in practical applications.