A new oligothiophene-derivatized fluorescent sensor for detecting and imaging of Hg2+ in water/soil/urine/tea/seafood samples and living plants.

Considering the high toxicity of Hg2+ to living organisms, accurately and sensitively detecting Hg2+ in environments, biology and food systems is of the utmost importance. Herein, we present a new fast-responsive oligothiophene-derivatized fluorescent sensor TTB for Hg2+ detection in real water/soil/urine/food samples. Sensor TTB shows a quick response, ultrahigh specificity, strong anti-disturbance, high-sensitivity with a satisfactory detection limit of 0.23 µM and good reversibility towards Hg2+. The response mechanism was well examined through Job's plot, FTIR spectra and DFT calculations. To examine naked-eye recognition of Hg2+, a visualization method by the TTB-coated test paper and cotton swabs was used for quickly detecting Hg2+. Additionally, sensor TTB shows good application flexibility and proves the capability for quantitative and accurate monitoring of Hg2+ levels in various water, soil, human urine, tea and seafood samples with an excellent efficiency. Moreover, fluorescence imaging experiments demonstrated that the TTB showed good cell-permeability and was utilized to detect/image Hg2+ in living plants. This study provides a powerful tool for accurately and reliably detecting Hg2+ in bio/environmental and food systems.