Journal
INORGANIC CHEMISTRY
Volume 52, Issue 16, Pages 9390-9398Publisher
AMER CHEMICAL SOC
DOI: 10.1021/ic4009569
Keywords
-
Categories
Funding
- National Science Foundation [1151665]
- NIH-CBITG [GM 08700]
- Department of Chemistry of the University of Minnesota
- Division Of Chemistry
- Direct For Mathematical & Physical Scien [1151665] Funding Source: National Science Foundation
Ask authors/readers for more resources
Molecular probes for the detection of hydroxyl radical (HO center dot) by time-delayed luminescence spectroscopy directly in water at neutral pH with high sensitivity and selectivity are presented. The bimolecular probes consist of a lanthanide complex with open coordination sites and a reactive pre-antenna composed of an aromatic acid or amide; the latter binds to and sensitizes terbium emission upon hydroxylation by HO center dot. These probes exhibit long luminescence lifetimes compatible with time-delayed measurements that remove interfering background fluorescence from the sample. Six different reactive pre-antenna (benzoate, benzamide, isophthalate, isophthalamide, trimesate, and trimesamide) and two different terbium complexes [Tb-(1,4,7,10-tetraazacyclododecane-1,4,7-tris(acetic acid)) (Tb-DO3A) and Tb-(1,4,7,10-tetraazacyclododecane-1,7-bis(acetic acid)) (Tb-DO2A)] were evaluated. Of these the trimesamide/Tb-DO3A system enables the most sensitive detection of HO center dot with an about 1000-fold increase in metal-centered time-delayed emission upon hydroxylation of the pre-antenna to 2-hydroxytrimesamide. Excellent selectivity for both the trimesamide/Tb-DO3A and trimesate/Tb-DO3A systems over other reactive oxygen and nitrogen species are observed. Notably, the increase in metal-centered luminescence intensity is not associated with a decrease in the hydration number (q) of Tb-DO3A, suggesting that the antenna is interacting with the lanthanide via a second sphere coordination environment or that coordination by the antenna occurs by displacement of one or more of the carboxylate arms of DO3A. Formation of a weak ternary complex Tb-DO3A center dot hydroxytrimesamide was confirmed by temperature-dependent titration and a decrease in K-app with increasing temperature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available