DNA dendrimer-templated copper nanoparticles: self-assembly, aggregation-induced emission enhancement and sensing of lead ions

Metal-Polymer Nanocomposites: A Promising Approach to Antibacterial Materials

There has been a new approach in the development of antibacterials in order to enhance the antibacterial potential. The nanoparticles are tagged on to the surface of other metals or metal oxides and polymers to achieve nanocomposites. These have shown significant antibacterial properties when compared to nanoparticles. In this article we explore the antibacterial potentials of metal-based and metal-polymer-based nanocomposites, various techniques which are involved in the synthesis of the metal-polymer, nanocomposites, mechanisms of action, and their advantages, disadvantages, and applications.

Micron-Scale Fabrication of Ultrathin Amorphous Copper Nanosheets Templated by DNA Scaffolds

Two-dimensional (2D) amorphous materials could outperform their crystalline counterparts toward various applications because they have more defects and reactive sites and thus could exhibit a unique surface chemical state and provide an advanced electron/ion transport path. Nevertheless, it is challenging to fabricate ultrathin and large-sized 2D amorphous metallic nanomaterials in a mild and controllable manner due to the strong metallic bonds between metal atoms. Here, we reported a simple yet fast (10 min) DNA nanosheet (DNS)-templated method to synthesize micron-scale amorphous copper nanosheets (CuNSs) with a thickness of 1.9 ± 0.4 nm in aqueous solution at room temperature. We demonstrated the amorphous feature of the DNS/CuNSs by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Interestingly, we found that they could transform to crystalline forms under continuous electron beam irradiation. Of note, the amorphous DNS/CuNSs exhibited much stronger photoemission (∼62-fold) and photostability than dsDNA-templated discrete Cu nanoclusters due to the elevation of both the conduction band (CB) and valence band (VB). Such ultrathin amorphous DNS/CuNSs hold great potential for practical applications in biosensing, nanodevices, and photodevices.

Cu2+-mediated turn-on fluorescence biosensor based on DNA-templated silver nanoclusters for label-free and sensitive detection of adenosine triphosphate

A Cu²⁺-mediated turn-on fluorescence biosensor based on the DNA-templated green-emitting silver nanoclusters (DNA@g-AgNCs) was developed for label-free and sensitive detection of adenosine 5'-triphosphate (ATP). Cu²⁺ was able to quench the bright green fluorescence of DNA@g-AgNCs because of the coordination and photoinduced electron transfer between DNA@g-AgNCs and Cu²⁺. Therefore, a unique and effective fluorescence biosensor can be constructed with the formation of DNA@g-AgNCs/Cu²⁺/ATP ternary-competition system. With the introduction of ATP, the DNA@g-AgNCs/Cu²⁺ fluorescence sensing system will be disrupted and the fluorescence of DNA@g-AgNCs was recovered due to higher affinity of ATP towards Cu²⁺. On the basis of this feature, the DNA@g-AgNCs/Cu²⁺ fluorescence sensing system demonstrated quantitative determination of ATP in the range 0.05 - 3 μM and a detection limit of 16 nM. Moreover, the fluorescence sensing system was successfully applied to the quantitative determination of ATP in human urine and serum samples with recoveries ranging from 98.6 to 106.5%, showing great promise to provide  a label-free, cost-efficient, and rapid platform for ATP-related clinical disease diagnosis.

Synthesis of Copper Nanocluster and Its Application in Pollutant Analysis

Copper nanoclusters (Cu NCs) with their inherent optical and chemical advantages have gained increasing attention as a kind of novel material that possesses great potential, primarily in the use of contaminants sensing and bio-imaging. With a focus on environmental safety, this article comprehensively reviews the recent advances of Cu NCs in the application of various contaminants, including pesticide residues, heavy metal ions, sulfide ions and nitroaromatics. The common preparation methods and sensing mechanisms are summarized. The typical high-quality sensing probes based on Cu NCs towards various target contaminants are presented; additionally, the challenges and future perspectives in the development and application of Cu NCs in monitoring and analyzing environmental pollutants are discussed.