A naphthalimide–rhodamine ratiometric fluorescent probe for Hg2+ based on fluorescence resonance energy transfer

A new FRET ratiometric fluorescent chemosensor for Hg2+ and its application in living EC 109 cells

“…The detection limit of L was at least 2.11 Â 10 À8 M (S- Fig. 7) according to the calculating formula (DL = d/S, d: standard deviation of response, S: slope), which has higher sensitivity than the FRET sensors Wu and Guo reported [31][32]. It was sensitive enough for the detection of Hg 2+ in industrial waste water, which had a discharge limit of 0.25 lM defined by the Standardization Administration (SA) of the People's Republic of China [38].…”

“…Compounds 1-5 were synthesized according to literatures [31][32][33]. Compound L was synthesized by a similar method to reported [34].…”

“…Because the pseudoStokes shifts of FRET based probes are larger than the Stokes shifts of either the donor or acceptor dyes, the possible self-quenching as well as fluorescence detection errors due to backscattering effects of the excitation source will be efficiently avoided [26]. However, despite many advantages, examples of the ratiometric fluorescence probes for Hg 2+ based on FRET are considerably limited [27][28][29][30][31][32].…”

Photophysical investigations of a FRET-based bifluorophoric conjugate and its Hg(II) specific ratiometric ‘turn-on’ signalling

“…In the context of selective detection of Hg(II) ion, many substituted rhodamine based probes have recently been reported exploiting a signal transduction pathway that involve in opening of rhodamine's spiro-ring through either metal ion coordination [17][18][19] or ion-induced chemical reactions [20,21]. Few such probes have also been reported to undergo signal modulation triggered by FRET initiation/inhibition processes for selective metal ion detection [22][23][24][25][26][27]. However, most of them involve tidieous multi-step synthetic routess with low yield and restricted functional flexibility in terms of practical applicability being operated in certain specified operational conditions of signal modulation.…”

Synthesis and properties of three novel rhodamine-based fluorescent sensors for Hg2+

“…Mercury is the third most frequently found and second most toxic heavy metal according to the research results of the Agency for Toxic Substances and Disease Registry (ATSDR) of the USA Department of Health and Human Services [1]. Due to easy absorptivity, high bioaccumulation and persistence, all elemental, inorganic and organic mercury can cause human health problems such as serious congnitive and motion disorders, kidney, central nervous system and prenatal brain damages [2].…”