Anhui Normal University

About: Anhui Normal University is a education organization based out in Wuhu, China. It is known for research contribution in the topics: Catalysis & Population. The organization has 7955 authors who have published 7309 publications receiving 117443 citations.

Application of functionalized CdS nanoparticles as fluorescence probe in the determination of nucleic acids

Abstract: Nanometer-sized fluorescent particles were successfully synthesized. The nanoparticles have a narrow, tunable, symmetric emission spectrum and a broad, continuous excitation spectrum. They are also photochemically stable. A synchronous fluorescence method was developed for the rapid determination of DNA with functionalized CdS as a fluorescence probe, based on the synchronous fluorescence quenching of functionalized CdS in the presence of DNA. Maximum fluorescence is produced at pH 7.0, with maximum excitation and emission wavelengths of 360 and 620 nm, respectively. The maximum emission wavelength of synchronous fluorescence is 354 nm when Δλ = 260 nm. Under optimum conditions, the calibration graphs are linear over the range 0–3.5 μg mL−1 for calf thymus DNA (CT-DNA) and 0.2–3.0 μg mL−1 for fish sperm DNA. The corresponding detection limit is 0.01 μg mL−1 for CT-DNA and 0.02 μg mL−1 for fish sperm DNA. The relative standard deviation of seven replicate measurements is 2.2% for 1 μg mL−1 calf thymus DNA and 2.4% for 1 μg mL−1 fish sperm DNA. The method is simple, rapid and sensitive. The recovery and relative standard deviation are very satisfactory.

Two-Photon Semiconducting Polymer Dots with Dual-Emission for Ratiometric Fluorescent Sensing and Bioimaging of Tyrosinase Activity

Abstract: Semiconducting polymer dots (Pdots) with one-, two-photon excitation and dual-emission have been synthesized by coprecipitation of two conjugated polymers including poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO) and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-(1-cyanovinylene-1,4-phenylene)] (CN-PPV) and have been further functionalized with l-tyrosine methyl ester (Tyr-OMe) via electrostatic assembly for ratiometric fluorescent sensing and bioimaging of tyrosinase activity. Tyrosinase-catalyzed oxidation of Tyr-OMe effectively modulate the dual-emission fluorescence of PFO/CN-PPV@Tyr-OMe Pdots from orange to blue through a selective photoinduced electron transfer (PET) process. A two-photon ratiometric sensor at almost zero-background interference and bioimaging of tyrosinase activity have been demonstrated, suggesting the potential biomedical applications of the prepared functionalized Pdots.

Security and Trust in Blockchains: Architecture, Key Technologies, and Open Issues

Abstract: As a new promising distributed technology, blockchains have been widely applied since its inception. Its decentralization feature reduces the reliance on the trusted authorities and third parties. It can well solve the problem of data being tampered and increase data sharing. However, a blockchain system faces various security and trust issues, such as attacks against consensus mechanisms and propagation processes, which may make it store malicious information or delay data propagation. The work discusses the basic architecture of blockchains as well as its potential security and trust issues at data, network, consensus, smart contract, and application layers. Then, the related literature work is analyzed in terms of the issues at these layers. Some open issues are presented and discussed.

Tailoring of White Luminescence in a NaLi 3 SiO 4 :Eu 2+ Phosphor Containing Broad-Band Defect-Induced Charge-Transfer Emission.

Abstract: Single-component materials with white-light emission are ideal for lighting applications. However, it is very challenging to achieve white luminescence in single-dopant activated solid phosphors. Herein, white NaLi3 Si1- x O4 :Eu2+ materials are designed via defect engineering and synthesized by reducing the Si content (0.15 ≤ x ≤ 0.25). Stochiometric NaLi3 SiO4 :Eu2+ exhibits a narrow-band blue emission at 469 nm, ascribed to the 5d → 4f transition of Eu2+ at highly symmetric cuboid Na sites, while samples with Si content reduced by 15-25% display white emission with two peaks at 472 nm and 585 nm. The newly appeared broadband yellow peak arises from charge-transfer transitions involving Eu2+ and nearby defects, as verified by an unusual bandwidth, a large Stokes shift, and a long decay time. A single-component white light-emitting diode device is fabricated by employing a white phosphor to demonstrate a color-rendering index of 82.9. This result provides a new design strategy for single-component white-light materials with broad-band defect-induced charge-transfer emission.