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

Considering the high toxicity of Hg to living organisms, accurately and sensitively detecting Hg in environments, biology and food systems is of the utmost importance. Herein, we present a new fast-responsive oligothiophene-derivatized fluorescent sensor TTB for Hg 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 Hg. The response mechanism was well examined through Job's plot, FTIR spectra and DFT calculations. To examine naked-eye recognition of Hg, a visualization method by the TTB-coated test paper and cotton swabs was used for quickly detecting Hg. Additionally, sensor TTB shows good application flexibility and proves the capability for quantitative and accurate monitoring of Hg 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 Hg in living plants. This study provides a powerful tool for accurately and reliably detecting Hg in bio/environmental and food systems.