Research Of DNA-templated Copper Nanoclusters Synthesis And Biological Application

Metal nanoclusters(MNCs) usually consist of a few to tens of metal atoms, it has attracted widespread attention due to their unique optical and electrical properties. Among them, DNA-templated MNCs are of tremendous interest because of their advantages including flexible synthesis method, tunable emission spectrum, high quantum yield, and good biocompatibility. In recent years, several MNCs have been studied extensively, which mainly include gold nanoclusters(Au NCs), silver nanoclusters(Ag NCs), and copper nanoclusters(Cu NCs). Cu NCs, by contrast, have special advantages in reagents(copper sulfate and ascorbic acid) source and cost-efficiency except similar photochemical property. However, the application of DNA-templated Cu NCs mainly focuses on chemical detection. Considering these superiorities, this work explores the applications of DNA-templated Cu NCs in DNA staining and the switch of DNA-mediated charge transport(DNA CT).1. The application research of DNA-templated copper nanoclusters in staining DNA in polyacrylamide gel electrophoresisThe safety of nucleic acid staining dyes has long been recognized to be a problem. Extensive efforts have been made to search for alternatives to the most popular but toxic staining dye, ethidium bromide(Et Br). However, so far no staining method that can be guaranteed to be sufficiently safe has been developed. In this paper, we report a green staining method of DNA in polyacrylamide gel electrophoresis, where in situ synthesis of Cu NCs in the gel is achieved to make the DNA bands visible under UV light. Moreover, a comprehensive study of the performance of this staining method has been conducted and the experimental results show that it has favorable sensitivity, stability, and usability. Meanwhile, in our animal experiments, the two reagents(copper sulfate and ascorbic acid) as well as the synthesized Cu NCs have been proven to be non-toxic in contact with skin. In addition, all the reagents employed in this work are readily available and low cost, and the procedure is simple to carry out. Therefore, this novel staining method based on the in situ synthesis DNA-templated fluorescent Cu NCs has many potential applications.2. The application research of DNA-templated copper nanoclusters in the switch of DNA-mediated charge transportToday, a consensus that DNA working as a molecular wire shows promise in nanoscale electronics is reached. Considering that the “ON-OFF” switch is the basis of a logic circuit, the switch of DNA-mediated charge transport should be conquered. Here, on the basis of chemical or electrochemical deposition and stripping of DNA-templated Cu NCs, we develop an “ON-OFF” nanoswitch for DNA CT. While Cu NCs are deposited, the DNA CT is blocked, which can be also recovered after stripping the Cu NCs. A switch cycle can be completed in a few seconds and can be repeated for many times. Moreover, by regulating the amount of reagents, deposition/stripping time, applied potential, etc., the switch is adjustable to make the wire at either an “ON-OFF” state or an intermediate state. We believe that this concept and the successful implementation will promote the practical application of DNA wire one step further.