Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-10-01

Journal: AQUATIC TOXICOLOGY

Included Journals: PubMed、SCIE

Volume: 191

Page Number: 105-112

ISSN: 0166-445X

Key Words: Daphnia magna,Fluoroquinolones,Functionalized graphene,Singlet oxygen,Time-gated luminescence imaging

Abstract: Singlet oxygen (O-1(2)) can be photogenerated by photoactive xenobiotics and is capable of causing adverse effects due to its electrophilicity and its high reactivity with biological molecules. Detection of the production and distribution of O-1(2) in living organisms is therefore of great importance. In this study, a luminescent probe ATTA- Eu3+ combined with time-gated luminescence imaging was adopted to detect the distribution and temporal variation of O-1(2) photoinduced by fluoroquinolone antibiotics and carboxylated/aminated graphenes in Daphnia magna. Results show that the xenobiotics generate O-1(2) in living daphnids under simulated sunlight irradiation (SSR). The photogeneration of O-1(2) by carboxylated/aminated graphenes was also confirmed by electron para magnetic resonance spectroscopy. The strongest luminescence signals of O-1(2) were observed in the hindgut of daphnids, and the signals in different areas of the daphnids (gut, thoracic legs and post-abdominal claw) displayed a similar trend of enhancement over irradiation time. Mean O-1(2) concentrations at different regions of daphnids within one hour of SSR irradiation were estimated to be in the range of 0.5 similar to 4.8 mu M. This study presented an efficient method for visualizing and quantifying the temporal and spatial distribution of O-1(2) photogenerated by xenobiotics in living organisms, which can be employed for phototoxicity evaluation of xenobiotics.