1. Bioconjugation of nanozyme and natural enzyme to enable a one-step cascade reaction for the detection of metabolites.
- Author
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Lang, Jin-Ye, Zhao, Jia-Meng, Ren, Ming-Jin, Wang, Xin-Yu, Chen, Le-Ping, Zhang, Xin-Chi, Wang, Xian-Hua, and Dong, Lin-Yi
- Subjects
METABOLITES ,ETHYLENE glycol ,BLOOD cholesterol ,ENZYMES ,MAGNETIC nanoparticles ,PEROXIDASE - Abstract
Nanozyme, with enzyme-mimicking activity and excellent stability, has attracted extensive attention. However, some inherent disadvantages, including poor dispersion, low selectivity, and insufficient peroxidase-like activity, still limit its further development. Therefore, an innovative bioconjugation of a nanozyme and natural enzyme was conducted. In the presence of graphene oxide (GO), histidine magnetic nanoparticles (H-Fe
3 O4 ) were first synthesized by a solvothermal method. The GO-supported H-Fe3 O4 (GO@H-Fe3 O4 ) exhibited superior dispersity and biocompatibility because GO was the carrier and possessed outstanding peroxidase-like activity because of the introduction of histidine. Furthermore, the mechanism of the peroxidase-like activity of GO@H-Fe3 O4 was the generation of •OH. Uric acid oxidase (UAO) was selected as the model natural enzyme and covalently linked to GO@H-Fe3 O4 with hydrophilic poly(ethylene glycol) as a linker. UAO could specifically catalyze the oxidation of uric acid (UA) to generate H2 O2 , and subsequently, the newly produced H2 O2 oxidized the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue ox-TMB under the catalysis of GO@H-Fe3 O4 . Based on the above cascade reaction, the GO@H-Fe3 O4 -linked UAO (GHFU) and GO@H-Fe3 O4 -linked ChOx (GHFC) were used for the detection of UA in serum samples and cholesterol (CS) in milk, respectively. The method based on GHFU exhibited a wide detection range (5–800 μM) and a low detection limit (1.5 μM) for UA, and the method based on GHFC exhibited a wide detection range (4–400 μM) and a low detection limit (1.13 μM) for CS. These results demonstrated that the proposed strategy had great potential in the field of clinical detection and food safety. [ABSTRACT FROM AUTHOR]- Published
- 2023
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