Near-infrared fluorescent probe for visualizing Se4+ and Zn2+ inhibition of Hg2+ uptake in plants and cell imaging

[Display omitted] •SN-Hg has high sensitivity, low detection limit and strong tissue penetration.•SN-Hg can detect Hg2+ in traditional Chinese medicine samples.•SN-Hg achieved in situ real-time and 3D imaging of Hg2+ in cells and plants.•The inhibitory effect of Se4+ or Zn2+ on Hg2+ uptake in plants was verified by SN-Hg. The advancement of industrialization has resulted in a significant influx of heavy metal ions into the ecological environment. Among these, the impact of Hg2+ on both plant growth and human health has garnered widespread attention. Therefore, it is imperative to address the removal of Hg2+ from the ecological environment. Here, our team has developed a near-infrared fluorescence probe, SN-Hg, for the detection of Hg2+. This probe offers several advantages including excellent selectivity, high sensitivity (LOD=85 nM), rapid response time and naked eye visualization. In addition, SN-Hg was successfully used to image the cells and the roots of plant (Platycodon grandiflorum seedlings) in situ. Moreover, the SN-Hg enabled 3D imaging of Hg2+ distribution in plants with a penetration depth of 80 μm. More importantly, the inhibitory effects of Se4+ and Zn2+ on the uptake of Hg2+ in Platycodon grandiflorum were further verified by SN-Hg. This study provides a foundation for soil protection and plant growth, as well as offering a new perspective for the removal of heavy metal pairs in ecological environments.