Efficient Biocatalytic System for Biosensing by Combining Metal-Organic Framework (MOF)-Based Nanozymes and G-Quadruplex (G4)-DNAzymes.
Xuanxiang MaoFangni HeDehui QiuShijiong WeiRengan LuoYun ChenXiaobo ZhangJianping LeiDavid MonchaudJean-Louis MergnyHuangxian JuJun ZhouPublished in: Analytical chemistry (2022)
A high catalytic efficiency associated with a robust chemical structure are among the ultimate goals when developing new biocatalytic systems for biosensing applications. To get ever closer to these goals, we report here on a combination of metal-organic framework (MOF)-based nanozymes and a G-quadruplex (G4)-based catalytic system known as G4-DNAzyme. This approach aims at combining the advantages of both partners (chiefly, the robustness of the former and the modularity of the latter). To this end, we used MIL-53(Fe) MOF and linked it covalently to a G4-forming sequence (F3TC), itself covalently linked to its cofactor hemin. The resulting complex (referred to as MIL-53(Fe)/G4-hemin) exhibited exquisite peroxidase-mimicking oxidation activity and an excellent robustness (being stored in water for weeks). These properties were exploited to devise a new biosensing system based on a cascade of reactions catalyzed by the nanozyme (ABTS oxidation) and an enzyme, the alkaline phosphatase (or ALP, ascorbic acid 2-phosphate dephosphorylation). The product of the latter poisoning the former, we thus designed a biosensor for ALP (a marker of bone diseases and cancers), with a very low limit of detection (LOD, 0.02 U L -1 ), which is operative in human plasma samples.
Keyphrases
- metal organic framework
- label free
- hydrogen peroxide
- room temperature
- global health
- bone mineral density
- crystal structure
- gold nanoparticles
- public health
- electron transfer
- soft tissue
- body composition
- human immunodeficiency virus
- quantum dots
- visible light
- postmenopausal women
- hepatitis c virus
- amino acid
- young adults
- high resolution