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

• The detection limit of probe for Hg2+ was 2.11 × 10−8 M (the ppb scale).
• High selectivity and sensitivity detection of in aqueous solution with a wide pH span (1.0–8.0).
• The significant changes in color could be used for naked-eye detection.
• The response time to Hg2+ is less than 2.5 min.
• The fluorescence imaging experiment demonstrated its value of practical application.

On the basis of fluorescent resonance energy transfer, a new fluorophore dyad (L) bearing rhodamine B and naphthalimide was developed as fluorescent ratiometric chemosensor for Hg2+ in aqueous solution. L exhibited high selectivity and excellent sensitivity towards Hg2+ with a broad pH span (1.0–8.0) and the detection limit of L was 2.11 × 10−8 M. Sensor L for the detection of Hg2+ was rapid and the recognizing event could complete in 2.5 min. A significant change in the color could be used for naked-eye detection. The selective fluorescence response of L to Hg2+ is due to the Hg2+-promoted ring opening of spirolactam of rhodamine moiety, leading to a cyclization reaction of thiourea moiety. In addition, fluorescence imaging experiments of Hg2+ in living EC 109 cells demonstrated its value of practical applications in biological systems.

On the basis of fluorescent resonance energy transfer, a new fluorophore dyad (L) bearing rhodamine B and naphthalimide was developed as fluorescent ratiometric chemosensor for Hg2+ in aqueous solution. L exhibited high selectivity and excellent sensitivity towards Hg2+ with a broad pH span (1.0–8.0) and the detection limit of L was 2.11 × 10−8 M. Sensor L for the detection of Hg2+ was rapid and the recognizing event could complete in 2.5 min. A significant change in the fluorescence color could be used for naked-eye detection. The selective fluorescence response of L to Hg2+ is due to the Hg2+-promoted ring opening of spirolactam of rhodamine moiety, leading to a cyclization reaction of thiourea moiety. In addition, fluorescence imaging experiments of Hg2+ in living EC 109 cells demonstrated its value of practical applications in biological systems.Figure optionsDownload as PowerPoint slide