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Updated: Jun 5, 2025

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
Cu-curcumin nanozyme for detection of Cr(VI) through an off-on strategy based on peroxidase mimicking activity
Ziwei Chai1, Aifang Zhou1, Jingjing Huang1
1College of Chemistry, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Food Laboratory of Zhongyuan, Zhengzhou University, Zhengzhou 450001, China. jiage@zzu.edu.cn.
Abstract:
Hexavalent chromium ions (Cr(VI)) possess inherent toxicity and propensity for bioaccumulation in the environment. Herein, a Cu-curcumin nanozyme was synthesized via a one-pot solvothermal method. Based on the high peroxidase-like activity of the Cu-curcumin nanozyme, a novel and economical colorimetric platform has been developed for Cr(VI) assay. In the presence of hydrogen peroxide (H2O2), the Cu-curcumin nanozyme can catalyze the transformation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into the blue product oxTMB. 8-Hydroxyquinoline (8-HQ) can inhibit the catalysis of the Cu-curcumin/TMB/H2O2 system, causing the blue color to fade. With the addition of Cr(VI), the peroxidase-like activity of the Cu-curcumin nanozyme is increased significantly, leading to the restoration of the Cu-curcumin/TMB/H2O2 system color. After optimization of the experimental parameters, a novel colorimetric sensor for Cr(VI) assay has been successfully developed with a low limit of detection (LOD) of 31.5 nM, affirming its potential for accurate Cr(VI) quantification in environmental specimens. In addition, paper strips integrated with a smartphone platform enhance the versatility and portability of the Cr(VI) assay, achieving an LOD of 0.1 μM.

