The self-assembling of the 10-methylacridinium perchlorate uorophore and azathiocrown ether derivative re- ceptor through sodium dodecyl sulfate (SDS) or sodium 4-octylbenzenesulfonate (SOBS) aggregates in water has allowed the realization of a new effective sensing system for Hg2þ ions. In the absence of metal ions, occurrence of the uorophore-receptor interaction was signaled through the uorescence quenching of acridinium. Upon addition of increasing quantities of Hg2þ, uorescence experiments pointed out an unusual further quenching of the acridinium uorescence, followed by an emission enhancement with a switching point around 1 � 10 7 and 1 � 10 8 M in SDS and SOBS, respectively. Such a behavior was attributed to the formation of mercury-receptor complexes with different coordination number and accordingly with distinct redox activity. The stoichiometry of the mercury complexes was assessed by spectrophotometric titration, while insights into their structures were obtained with density functional theory (DFT) calculation. Hg2þ ions can be selectively detected in SDS solutions, and its concentration in the nanomolar range can be linearly determined. Altogether, this modular approach allows quick variation of the components, which makes the optimal tuning of the process up to its maximum ef ciency level very easy.

Turn-off and -on fluorescence switching of a self-assembled sensor for mercury(II) induced by anionic micelles

Germani R.;Belpassi L.;Elisei F.;Tiecco M.;Del Giacco T.
2020

Abstract

The self-assembling of the 10-methylacridinium perchlorate uorophore and azathiocrown ether derivative re- ceptor through sodium dodecyl sulfate (SDS) or sodium 4-octylbenzenesulfonate (SOBS) aggregates in water has allowed the realization of a new effective sensing system for Hg2þ ions. In the absence of metal ions, occurrence of the uorophore-receptor interaction was signaled through the uorescence quenching of acridinium. Upon addition of increasing quantities of Hg2þ, uorescence experiments pointed out an unusual further quenching of the acridinium uorescence, followed by an emission enhancement with a switching point around 1 � 10 7 and 1 � 10 8 M in SDS and SOBS, respectively. Such a behavior was attributed to the formation of mercury-receptor complexes with different coordination number and accordingly with distinct redox activity. The stoichiometry of the mercury complexes was assessed by spectrophotometric titration, while insights into their structures were obtained with density functional theory (DFT) calculation. Hg2þ ions can be selectively detected in SDS solutions, and its concentration in the nanomolar range can be linearly determined. Altogether, this modular approach allows quick variation of the components, which makes the optimal tuning of the process up to its maximum ef ciency level very easy.
2020
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/1454633
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