Shenzhen University

About: Shenzhen University is a education organization based out in Shenzhen, China. It is known for research contribution in the topics: Computer science & Laser. The organization has 28054 authors who have published 35378 publications receiving 522023 citations.

Black phosphorus quantum dot based novel siRNA delivery systems in human pluripotent teratoma PA-1 cells

Abstract: As a novel semiconducting material, the inherent, direct, and appreciable band gap endows BP with preferable optical and electronic properties other than graphene and transition metal dichalcogenides. In addition, bio-related applications with equal importance also attract great attention thanks to several inherited advantages of BP including large drug loading capacity, high PDT efficiency, high biocompatibility and degradability. However, to date there is limited research about the biomedical applications of BP. In this study, we reported the engineering of polyelectrolyte polymers coated BP quantum dots (BP-QDs)-based nanocarriers to deliver small interfering RNA (siRNA) into human ovarian teratocarcinoma PA-1 cells. Compared to the commercial delivery reagents, superior transfection efficiency of BP-QD was detected. The expression of the LSD1 (lysine-specific demethylase 1) mRNA in PA-1 cells was significantly suppressed by BP-QDs-LSD1 siRNA complex. Notably, BP-QDs possess excellent biocompatibility and low cytotoxicity even at concentrations as high as 5 mg mL−1. The combination treatment of BP nanodots-LSD1 siRNA complex with NIR light could inhibit the cell growth rate by more than 80%. In conclusion, this is the first application of BP-QDs as gene delivery systems, which shows promising potential for siRNA delivery and photothermal effects in cancer therapy.

Lithium Silicide Surface Enrichment: A Solution to Lithium Metal Battery

Abstract: The propensity of lithium dendrite formation during the charging process of lithium metal batteries is linked to inhomogeneity on the lithium surface layer. The high reactivity of lithium and the complex surface structure of the native layer create "hot spots" for fast dendritic growth. Here, it is demonstrated that a fundamental restructuring of the lithium surface in the form of lithium silicide (Lix Si) can effectively eliminate the surface inhomogeneity on the lithium surface. In situ optical microscopic study is carried out to monitor the electrochemical deposition of lithium on the Lix Si-modified lithium electrodes and the bare lithium electrode. It is observed that a much more uniform lithium dissolution/deposition on the Lix Si-modified lithium anode can be achieved as compared to the bare lithium electrode. Full cells paring the modified lithium anode with sulfur and LiFePO4 cathodes show excellent electrochemical performances in terms of rate capability and cycle stability. Compatibility of the anode enrichment method with mass production process also offers a practical way for enabling lithium metal anode for next-generation lithium batteries.

Size-dependent nonlinear optical properties of black phosphorus nanosheets and their applications in ultrafast photonics

Abstract: Multi-layer black phosphorus nanosheets (BPs) with different sizes are synthesized by using a basic solvent exfoliation method in association with controlled gradient centrifugation. Size-dependent nonlinear saturable absorption and Kerr nonlinearity as well as ultrafast carrier dynamics of BPs is systematically studied by using a Z-scan and pump–probe technique. Furthermore, an ultrashort pulse with a pulse duration of about 635 fs centered at a wavelength of 1562 nm is generated by using smaller sized BPs as a saturable absorber. These results directly reveal the physical processes of size-dependent nonlinear optical (NLO) properties of BPs and provide researchers with a viable approach in tailoring the NLO response of BPs through controlling the sizes, paving the way towards BP based electronics and optoelectronics applications such as ultrafast optical switches, modulators, fiber lasers, etc.