Related Experiment Video
Updated: Jul 6, 2026
08:23
Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
Hollow nanozyme with improved peroxidase-like activity for nitrite detection
Kequan Yao1, Junjun Lu1, Xinjiao Wang2
1Department of Chemistry, College of Science, Northeastern University, Shenyang, 110819, P. R. China.
Mikrochimica Acta
|July 4, 2026
Summary
A novel nanozyme, Fe3C/Mo2C hollow spheres, enables rapid point-of-care nitrite detection. This method uses a smartphone colorimetric assay for accurate and selective analysis in food and water samples.
Area of Science:
- Materials Science: Synthesis and characterization of novel Fe3C/Mo2C hollow spheres.
- Nanotechnology: Application of nanozymes for chemical sensing.
- Analytical Chemistry: Development of point-of-care detection methods.
Background:
- Nitrite (NO2-) is a significant pollutant and carcinogen, necessitating urgent development of detection methods.
- Existing detection methods may lack the speed, sensitivity, or portability required for point-of-care applications.
- Nanozymes offer promising catalytic properties for sensitive and selective chemical detection.
Purpose of the Study:
- To synthesize and characterize Fe3C/Mo2C hollow spheres (Fe3C/Mo2CHS) as a novel nanozyme.
- To investigate the peroxidase-like (POD-like) activity of Fe3C/Mo2CHS.
- To develop a point-of-care (POC) digital image colorimetric method for nitrite detection using Fe3C/Mo2CHS and a smartphone.
Main Methods:
- Synthesis of Fe3C/Mo2C hollow spheres (Fe3C/Mo2CHS).
- Evaluation of the POD-like activity of Fe3C/Mo2CHS using kinetic studies (Km, Vmax).
- Development of a colorimetric assay involving TMB oxidation and subsequent reaction with nitrite, detected via smartphone imaging.
Main Results:
- Fe3C/Mo2CHS demonstrated superior POD-like activity compared to Fe3C and Mo2C.
- A linear response for nitrite detection was observed in the range of 2-300 µM.
- The developed method achieved a low limit of detection (LOD) of 2.09 µM with high selectivity and reproducibility.
Conclusions:
- Fe3C/Mo2CHS serves as an effective nanozyme with enhanced POD-like activity due to heterointerface effects.
- The smartphone-based colorimetric method provides a sensitive, selective, and portable approach for point-of-care nitrite detection.
- This method shows potential for practical application in monitoring nitrite levels in food and water samples.
