Phosphatase-mimicking Zr@PDA nanozyme with excellent dispersion stability for the detection of fructose 1,6-diphosphate.

Zr4+-doped polydopamine (Zr@PDA) nanozyme with phosphatase-like activity was synthesized by a one-pot hydrothermal method for the first time. Compared with previous representative phosphatase-mimicking nanozymes (i.e., CeO2 NPs, ZrO2 NPs and UiO-66), Zr@PDA not only exhibited higher dispersion stability in water, but also higher catalytical efficiency. Kcat/Km of Zr@PDA is 35 and 12 times that of UiO-66 and ZrO2 NPs, respectively, which would endow the Zr@PDA-based analytical methods with high sensitivity. As a demonstration, a novel colorimetric method based on Zr@PDA nanozyme was developed for sensitive detection of the drug fructose 1,6-diphosphate. The linear range is 1-15 µM with a detection limit as low as 0.38 µM.

Boron nanosheets as a phosphatase mimicking nanozyme with ultrahigh catalytic activity for prodrug-based cancer therapy.

Boron nanosheets (BNSs) are reported as a new phosphatase mimicking nanozyme. Surprisingly, the catalytic rate of BNSs is up to 17 times those of known phosphatase mimicking nanozymes. By adding polyols and Lewis bases, the catalytic activity of BNSs was attributed to the Lewis acidity of the B centers of the BNSs. Theoretical investigation shows that the B centers are responsible for the catalytic hydrolysis of phosphoesters. Moreover, the biomimetic activity of the BNSs was further explored for enhancing anticancer therapy through nanozyme-catalyzed prodrug conversion.

Accelerating the Phosphatase-like Activity of Uio-66-NH2 by Catalytically Inactive Metal Ions and Its Application for Improved Fluorescence Detection of Cardiac Troponin I.

Compared with natural enzymes, nanozymes usually exhibit much lower catalytic activities, which limit the sensitivities of nanozyme-based immunoassays. Herein, several metal ions without enzyme-like activities were engineered onto Uio-66-NH2 nanozyme through postsynthetic modification. The obtained Mn+@Uio-66-NH2 (Mn+ = Zn2+, Cd2+, Co2+, Ca2+and Ni2+) exhibited improved phosphatase-like catalytic activities. In particular, a 12-fold increase in the catalytic efficiency (kcat/Km) of Uio-66-NH2 was observed after the modification with Zn2+. Mechanism investigations indicate that both the amino groups and oxygen-containing functional groups in Uio-66-NH2 are the binding sites of Zn2+, and the modified Zn2+ ions on Uio-66-NH2 serve as the additional catalytic sites for improving the catalytic performance. Furthermore, the highly active Zn2+@Uio-66-NH2 was used as a nanozyme label to develop a fluorescence immunoassay method for the detection of cardiac troponin I (cTnI). Compared with pristine Uio-66-NH2, Zn2+@Uio-66-NH2 can widen the linear range by 1 order of magnitude (from 10 pg/mL-1 µg/mL to 1 pg/mL-1 µg/mL) and also lower the detection limit by 5 times (from 4.7 pg/mL to 0.9 pg/mL).

Pd-catalyzed asymmetric intramolecular aryl C-O bond formation with SDP(O) ligand: enantioselective synthesis of (2,3-dihydrobenzo[b][1,4]dioxin-2-yl)methanols.

Employing a chiral spirodiphosphine monoxide ligand with 1,1'-spirobiindane backbone (SDP(O)), a desymmetrization strategy of Pd-catalyzed intramolecular asymmetric aryl C-O coupling of 2-(2-halophenoxy)propane-1,3-diols, was developed. The SDP(O) ligand shows much better results than its SDP counterpart. The protocol provides an efficient and highly enantioselective method for the synthesis of 2-hydroxymethyl-1,4-benzodioxanes. Density functional theory studies provide a model that accounts for the origin of the enantioselectivity.

Copper-catalyzed enantioselective intramolecular aryl C-N coupling: synthesis of enantioenriched 2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxamides via an asymmetric desymmetrization strategy.

The differentiation of two nucleophilic amide groups in malonamides through a copper-catalyzed enantioselective intramolecular aryl C-N coupling reaction is demonstrated based on an asymmetric desymmetrization strategy. Such a method afforded enantioenriched 2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxamides in high yields and moderate to good enantioselectivity.