Metal-pyrimidine nanocubes immobilized enzymes with pH-switchable multienzyme-like activity for broad-pH-responsive sensing assay for organophosphorus pesticides.

Peroxidase (POD)-like can only function in acidic environments and the pH mismatch restricts the application of enzyme-nanozyme cascade catalytic sensing platforms in the broad-pH-responsive assay for organophosphorus pesticides (OPs). Herein, the metal-pyrimidine nanocubes (MPNCs) with intrinsic pH-switchable POD-like and catalase (CAT)-like properties were synthesized via the coordination of pyrimidin-2-ol with Cu. Meanwhile, acetylcholinesterase (AChE) and choline oxidase (CHO) were simultaneously encapsulated in MPNCs to construct an enzyme-nanozyme cascade catalytic platform (AChE/CHO@MPNCs).

Biomimetic Metal-Pyrimidine Nanoflowers: Enzyme Immobilization Platforms with Boosted Activity.

For the enzyme immobilization platform, enhancing enzyme activity retention while improving enzyme stability remains a challenge for sensitive sensing analysis. Herein, an in situ biomimetic immobilized enzyme carrier (metal-pyrimidine nanoflowers, MPNFs) synthesized by the coordination of DNA base derivative (2-aminopyrimidine) with Zn in the aqueous phase at room temperature is developed. The biocompatibility of 2-aminopyrimidine and the hydrophilicity and green synthetic conditions of MPNFs allows the immobilized enzymes to retain above 91.

In situ encapsulation of laccase in mesoporous amorphous ZIF-8 for Reactive Blue 19 removal.

Laccase with substrate non-specificity is particularly effective in pollutant degradation. However, the practical application of the laccase is limited due to its poor stability and reusability. In this study, a simple in situ encapsulation method was used to immobilize laccase into amorphous zeolitic imidazolate frameworks-8 (aZIF-8), and the synthesized Lac@aZIF-8 biocomposites were used to remove Reactive Blue 19 (RB 19).

Dual-channel fluorescence detection of antibiotic resistance genes based on DNA-templated silver nanoclusters.

The aqueous environment is an ideal site for the generation and transmission of antibiotic resistance genes (ARGs), and has become a sink for multiple ARGs. Detection of multiple ARGs in one-pot by a simple method is essential to control the spread of antibiotic resistance. Herein, we developed a novel fluorescence sensing strategy based on chameleon DNA-templated silver nanoclusters (AgNCs) to achieve simultaneous detection of two ARGs (tet-A and sul-1).