Li Zhou

DNA‐mediated Construction of Hollow Upconversion Nanoparticles for Protein Harvesting and Near‐Infrared Light Triggered Release

A simple DNA-mediated solvothermal method has been developed for the construction of well-defined hollow UNPs that can be used for a new paradigm to realize NIR light-controlled non-invasive protein release. In vitro studies show that the UNPs are capable of the transportation of enzyme into living cells. Intracellular NIR triggers the release of enzymes with high spatial and temporal precision and the released enzyme also retains its biological activity.

Chiral Lewis Base Catalyzed Highly Enantioselective Reduction of N‐Alkyl β‐Enamino Esters with Trichlorosilane and Water

First, test the water! In the presence of a chiral Lewis base catalyst 2, the supposedly moisture-unfriendly reduction system with trichlorosilane was found to be highly efficient and enantioselective when using water as an additive. For the first time, this method enables the reduction of a broad range of N-alkyl beta-enamino esters 1 to give N-alkyl beta-amino esters 3 in good to high yields and with excellent enantioselectivities (see scheme).

DNA-mediated biomineralization of rare-earth nanoparticles for simultaneous imaging and stimuli-responsive drug delivery

A DNA-guided method for surface engineering of NaGdF4:Ce/Tb hybrid nanoparticle has been proposed. In this study, the DNA molecules that retained after one-pot NaGdF4:Ce/Tb synthesis is directly utilized as biotemplate for CaP heterogeneous nucleation, thus the dual-purpose function of DNA is realized in the current study which could afford a new type of pH-responsive theranostic platform to enhance the therapeutic efficiency while minimizing side effects. The introduction of another layer of aptamer molecules on CaP facilitated cellular uptake of the resulting nanocomposite into specific target cells via receptor-mediated endocytosis. After been taken by the target tumor cells, the NaGdF4:Ce/Tb@CaP was found to be mostly accumulated in lysosome, which facilitated the dissolving of CaP coatings as non-toxic ions to initiate drug release and efficient cancer cell destruction. We envision that the hybrid nanocarrier may serve as practical and multifunctional probe for cancer therapy and the presented synthesis approach here may also benefit the preparation of many other types of multifunctional inorganic-biomolecular hybrid nanostructures based on the DNA nanotechnology.

Ionic liquid-assisted synthesis of multicolor luminescent silica nanodots and their use as anticounterfeiting ink.

Here we propose a simple route for the fabrication of silica nanodots which are strongly photoluminescent in both solution and the solid state based on the use of ionic liquids (ILs). It is found that the ILs not only provides the environment for the reaction but also contributes to the quantum yield (QY) of the silica nanodots. In particular, the produced silica nanodots also displayed excitation-dependent photoluminescence and temperature sensitive properties. Based on the unique optical properties, the as-prepared nanomaterial was used for anticounterfeiting application and the results demonstrated the great potential of the silica nanodots alone or combined with other fluorescent material of unicolor for an improved anticounterfeiting technology. This simple approach and the resulting outstanding combination of properties make the prepared silica nanodots highly promising for myriad applications in areas such as fluorescent anticounterfeiting, optoelectronic devices, medical diagnosis and biological imaging.

Evolution of chiral Lewis basic N-formamide as highly effective organocatalyst for asymmetric reduction of both ketones and ketimines with an unprecedented substrate scope

L-Pipecolinic acid derived Lewis basic N-formamide has been developed as a first highly effective catalyst for the asymmetric reduction of aromatic and aliphatic ketones as well as aromatic and aliphatic ketimines in good to high enantioselectivity.

Coupling exonuclease III with DNA metallization for amplified detection of biothiols at picomolar concentration

For early diagnosis of diseases, the need of ultralow detection limit is an ongoing quest. In this work, by taking the uniqueness of Exonuclease III and DNA metallization, we demonstrate a facile turn-on fluorescent method for amplified detection of biothiols at picomolar concentration. This method relies on the amplification process achieved by the recycling of biothiols retrieved target DNA from silver depositions and the specific interactions between quadruplex and NMM. This method is simple in design, economic in operation and exhibits ultralow detection limit and excellent selectivity toward thiol-containing biomolecules among amino acids found in proteins and in serum samples. More importantly, the detection and discrimination process can be seen by the naked eye with the aid of an UV transilluminator. Therefore, this new concept may offer a potential approach for practical applications as an efficient biosensor for early detection of diseases.

Reductive Hydrazination with Trichlorosilane: A Method for the Preparation of 1,1-Disubstituted Hydrazines.

A straightforward and facile method has been developed to prepare 1,1-disubstituted hydrazines via Lewis base promoted direct reductive hydrazination. Under the catalysis of hexamethylphosphoramide (HMPA) and N,N-dimethylacetamide (DMAc), respectively, various ketones and aldehydes could react with phenylhdrazines to prepare 1,1-disubstituted hydrazines with good to high yields.

Growth of Hydrophilic CuS Nanowires via DNA‐Mediated Self‐Assembly Process and Their Use in Fabricating Smart Hybrid Films for Adjustable Chemical Release

Facile growth of CuS nanowires through self-assembly and their application as building blocks for near-infrared light-responsive functional films have been demonstrated. It is found that DNA is a key factor in preparing the CuS material with defined nanostructure. An exclusive oriented self-aggregate growth mechanism is proposed for the growth of the nanowires, which might have important implications for preparing advanced, sophisticated nanostructures based on DNA nanotechnology. By employing the hydrophilic CuS nanowire as an optical absorber and thermosensitive nanogel as guest reservoir inside alginate film, a new platform for the release of functional molecules has been set up. In vitro studies have shown that the hybrid film possesses excellent biocompatibility and the release rate of chemical molecules from the film could be controlled with high spatial and temporal precision. Our novel approach and the resulting outstanding combination of properties may advance both the fields of DNA nanotechnology and light-responsive devices.