Fluorescent sensing of ascorbic acid based on iodine induced oxidative etching and aggregation of lysozyme-templated silver nanoclusters.

Title Fluorescent sensing of ascorbic acid based on iodine induced oxidative etching and aggregation of lysozyme-templated silver nanoclusters.
Authors Q. Mo; F. Liu; J. Gao; M. Zhao; N. Shao
Journal Anal Chim Acta
DOI 10.1016/j.aca.2017.11.068
Abstract

In this work, we developed a sensitive and highly selective fluorescent approach for the detection of ascorbic acid (AA) by taking advantage of the oxidative etching effect of iodine (I2) on the lysozyme-stabilized silver nanoclusters (dLys-AgNCs) with fluorescence quenching. I2 could be produced from the redox reaction between iodate (IO3-) and AA, and thus the fluorescence intensity of dLys-AgNCs was turned off significantly in the coexistence of IO3- and AA. The fluorescence quenching of dLys-AgNCs had a good linear relationship with AA concentration, which allowed the detection of AA in the range from 0.05 to 45.0 ?mol L-1 with a detection limit of 20 nmol L-1. The quenching mechanism was elucidated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), zeta potential, and dynamic light scattering (DLS) measurements, confirming that the fluorescence quenching of the dLys-AgNCs was attributed to the oxidative etching of the in situ generated I2, inducing aggregation of the dLys-AgNCs probe by forming Ag@AgI nanocomposite. The dLys-AgNCs probe exhibited excellent selectivity for AA sensing over several common reducing agents tested. Moreover, this approach was extended to the detection of AA in orange juice and urine with recovery rates in the range of 96.0% (RSD: 4.11) to 100.9% (RSD: 3.28) and 94.5% (RSD: 6.40) to 99.2% (RSD: 5.36), respectively.

Citation Q. Mo; F. Liu; J. Gao; M. Zhao; N. Shao.Fluorescent sensing of ascorbic acid based on iodine induced oxidative etching and aggregation of lysozyme-templated silver nanoclusters.. Anal Chim Acta. 2018;1003:4955. doi:10.1016/j.aca.2017.11.068

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Iodine

See more Iodine products. Iodine (atomic symbol: I, atomic number: 53) is a Block P, Group 17, Period 5 element with an atomic radius of 126.90447. The number of electrons in each of Iodine's shells is 2, 8, 18, 18, 7 and its electron configuration is [Kr] 4d10 5s2 5p5. The iodine atom has a radius of 140 pm and a Van der Waals radius of 198 pm. In its elemental form, iodine has a lustrous metallic gray appearance as a solid and a violet appearance as a gas or liquid solution. Elemental IodineIodine forms compounds with many elements, but is less active than the other halogens. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide. Iodine compounds are important in organic chemistry and very useful in the field of medicine. Iodine was discovered and first isolated by Bernard Courtois in 1811. The name Iodine is derived from the Greek word "iodes" meaning violet.

Silver

See more Silver products. Silver (atomic symbol: Ag, atomic number: 47) is a Block D, Group 11, Period 5 element with an atomic weight of 107.8682. Silver Bohr ModelThe number of electrons in each of Silver's shells is 2, 8, 18, 18, 1 and its electron configuration is [Kr]4d10 5s1. The silver atom has a radius of 144 pm and a Van der Waals radius of 203 pm. Silver was first discovered by Early Man prior to 5000 BC. In its elemental form, silver has a brilliant white metallic luster. Elemental SilverIt is a little harder than gold and is very ductile and malleable, being exceeded only by gold and perhaps palladium. Pure silver has the highest electrical and thermal conductivity of all metals and possesses the lowest contact resistance. It is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide, or air containing sulfur. It is found in copper, copper-nickel, lead, and lead-zinc ores, among others. Silver was named after the Anglo-Saxon word "seolfor" or "siolfur," meaning 'silver'.

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