This paper reports a simple, rapid and sensitive fluorescence sensor for the parallel determination of iron (III) (Fe 3+ ), terbium (III) (Tb 3+ ) and europium (III) (Eu 3+ ) ions using Carbon Dot (CD) serving as a fluorescence probe. The Carbon Dot (CD), which was synthesized via an acid-cutting method using anthracite coal as the carbon source, was found to have rich carboxyl and hydroxyl groups on its surface. The fluorescence of the as-prepared CD can be selectively quenched by the Fe 3+ ion via non-radiative electron-transfer, and furthermore, the as-prepared CD can also sensitize the luminescence of both Tb 3+ and Eu 3+ ions through the antenna effect and enhance the fluorescence of Tb 3+ and Eu 3+ by more than several orders of magnitude. Therefore, the as-prepared CD was applied as a fluorescence probe towards the parallel determination of Fe 3+ , Tb 3+ and Eu 3+ and exhibited detection limits in 0.019, 0.10 and 0.79 μM, respectively. The fluorescence quenching mechanism and energy transfer mechanism were also studied in details.
Wang Aiqing,Cui Yuezhi,Tao Furong,Gu Caihong,Wang Shijie,Li Tianduo
A functionalized glass sensor ( G-P ) was prepared for detecting nitroaromatic compounds (NACs) by chemically immobilizing a conjugated polymer P on the surface of a glass slide. The monolayer film sensor had several advantages: the signal amplification effect of conjugated polymers, no leakage of sensing materials in solution, and good permeability for the analytes. Fluorescence quenching studies demonstrated that the sensor was highly sensitive to NACs. When the DNT concentration was 1.03 × 10 –7 mol/L, the quenching efficiency (1– I / I
0 ) of G-P reached 52.8%. Moreover, the excellent properties of reversibility, selectivity and sensitivity indicated the glass G-P might be a promising sensor in the field of explosives detection.
A polyethylene terephthalate nano porous luminescence fiber (PNPLF) was prepared through electrospun technology. The SEM and TEM images show that the surfaces of the fibers are covered with pores. The diameter of the fiber is 250–500 nm, and the diameter of the pores is 20–180 nm. The water and oil contact angles of PNPLF are 135° and 27°, respectively. The oil absorption value of the as-prepared PNPLF achieves 135 g/g and has a good oil absorption function. The as-prepared PNPLF has good luminescence properties and fluorescent-indicating function. Even trace amounts of oil can also cause obvious change of fluorescence intensity of PNPLF which has a good stability from 20 °C to 70 °C. The breaking stress of yarn of PNPLF reaches 117cN. Furthermore, the good mechanical properties and thermal properties of PNPLF provide important basic conditions for their wide applications.