The Effect of Local Dielectric Environment on the Fluorescence Quenching Efficiency of Gold Nanoshell

A dual recognition system with a fluorescence quenching of quantum dots (QDs) and specific recognition of molecularly imprinted polymer (MIP) for the detection of chloramphenicol (CAP) was constructed. MIP@SiO2@QDs was prepared by reverse microemulsion method with 3-aminopropyltriethoxysilane (APTS), tetraethyl orthosilicate (TEOS) and QDs being used as the functional monomer, cross-linker and signal sources, respectively. MIP can specifically recognize CAP, and the fluorescence of QDs can be quenched by CAP due to the photo-induced electron transfer reaction between CAP and QDs. Thus, a method for the trace detection of CAP based on MIP@SiO2@QDs fluorescence quenching was established. The fluorescence quenching efficiency of MIP@SiO2@QDs displayed a desirable linear response to the concentration of CAP in the range of 1.00~4.00 × 102 μmol × L−1, and the limit of detection was 0.35 μmol × L−1 (3σ, n = 9). Importantly, MIP@SiO2@QDs presented good detection selectivity owing to specific recognition for CAP, and was successfully applied to quantify CAP in lake water with the recovery ranging 102.0~104.0%, suggesting this method has the promising potential for the on-site detection of CAP in environmental waters.

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Enhancement of the Fluorescence Quenching Efficiency of DPPH• on Colloidal Nanocrystalline Quantum Dots in Aqueous Micelles

Journal of Fluorescence ◽

10.1007/s10895-011-0893-4 ◽

2011 ◽

Vol 21 (5) ◽

pp. 1941-1949 ◽

Cited By ~ 8

Author(s):

Tuanjai Noipa ◽

Surangkhana Martwiset ◽

Nutthaya Butwong ◽

Thawatchai Tuntulani ◽

Wittaya Ngeontae

Keyword(s):

Quantum Dots ◽

Fluorescence Quenching ◽

Quenching Efficiency ◽

Aqueous Micelles

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Fluorescence quenching of Safranine T by inorganic anions in Tween micelles

Canadian Journal of Chemistry ◽

10.1139/v05-225 ◽

2005 ◽

Vol 83 (12) ◽

pp. 2067-2072 ◽

Cited By ~ 5

Author(s):

Stephanie A Moore ◽

Sarah E Moore ◽

Karen M Glenn ◽

Subhash C Bhattacharya ◽

Rama M Palepu

Keyword(s):

Fluorescence Quenching ◽

Inorganic Anions ◽

Tween 20 ◽

Micellar Media ◽

Collisional Quenching ◽

Quenching Rate ◽

Photophysical Process ◽

Iodide Ion ◽

Safranine T ◽

Quenching Efficiency

The fluorescence quenching of the dye Safranine T by various inorganic anions such as [Fe(CN6)]3, [Fe(CN6)]4, I, Br, NO2, and N3 in aqueous solution and in nonionic micellar solutions of Tweens (Tween 20, Tween 40, and Tween 80) was studied. The SternVolmer quenching constants and quenching rate constants were evaluated. Compared to the quenching efficiency in aqueous media, that of the micellar media was found to be lower, except when iodide ion was used as a quencher. With the exception of the iodide ion, it has been established that collisional quenching plays a major role in the photophysical process. In the case of the iodide ion, both static and collisional quenching processes play a major role, owing to the complexation of iodide ion with Tween micelles. The SternVolmer quenching constants were found to be dependent on the ionic strength of the medium.Key words: fluorescence, static quenching, Tweens, SternVolmer constant, micellar media.

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