Chem. J. Chinese Universities ›› 2025, Vol. 46 ›› Issue (1): 20240341.doi: 10.7503/cjcu20240341

• Article • Previous Articles     Next Articles

Component-tunable PdRh Bimetallic Nanozyme for Ultra-sensitive Colorimetric Detection of Nitrite

TANG Yuxi1,2, YANG Qi2(), ZHI Xinpeng1,2, CHEN Mengyuan2, LIU Siyuan2, LI Jiachang2, LIU Ziyang2, JIA Huimin2, TONG Yuping1(), HE Weiwei2   

  1. 1.School of Materials Science and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China
    2.Key Laboratory of Micro?Nano Materials for Energy Storage and Conversion of Henan Province,Institute of Surface Micro and Nano Materials,College of Chemical and Materials Engineering,Xuchang University,Xuchang 461000,China
  • Received:2024-07-05 Online:2025-01-10 Published:2024-08-15
  • Contact: YANG Qi E-mail:yangq@xcu.edu.cn;yptong_zz@163.com
  • Supported by:
    the National Natural Science Foundation of China(62274141);the Key Scientific and Technological Project of Henan Province, China(242102230074)

Abstract:

A series of bimetallic nanozymes(Pd3Rh, PdRh, PdRh3) was prepared using one-pot hydrothermal method by adjusting the ratio of palladium(Pd) to rhodium(Rh). The peroxidase-like(POD-like) and oxidase-like(OXD-like) activities of nanozymes were tested. The results showed that the catalytic activity of bimetallic nanozymes was significantly enhanced compared to that of single metallic nanozymes(Pd, Rh). The POD-like and OXD-like activities exhibited obvious component dependence, and PdRh3 and PdRh nanozyme showed the strongest POD-like and OXD-like activity, respectively. The analysis of enzymatic kinetics showed that the Michaelis-Menten constant (Km) of PdRh3 nanozyme with 3,3',5,5'-tetramethylbenzidine(TMB) and H2O2 as substrates are 15.65 and 381.99 μmol/L, respectively. The corresponding maximum velocity(vmax) reach 8.40×10-8 and 11.01×10-8 mol/(L·s). In addition, the POD-like activity of PdRh3 nanozyme was pH-dependent, and the optimized activity was obtained at pH=5. A colorimetric sensing system was developed based on PdRh3 nanozyme, which realized the rapid quantitative detection of nitrite concentration in solution according to the fitting relationship between the absorbance ratio(A445 nm/A652 nm) and the concentration of nitrite ion(NO2-). The limit of detection(LOD) in pH=5 buffer and pure water are 0.467 and 30.523 μmol/L, respectively, and the system has a good specificity under the interference of various salt ions, demonstrating great application potential in biosensing.

Key words: Nanozymes, Component regulation, Enzyme-like activity, Nitrite detection

CLC Number: 

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