Highly sensitive fluorescent sensor for hypochlorite in nearly 100% aqueous solution and its application for live-cell, plant and zebrafish imaging

A new ICT type D-pi-A structured chemosensor DTB derived from a bithiophene-benzothiazole derivative has been synthesized. Sensor DTB showed a colorimetric and fluorometric dual-signaling response to hypochlorite (ClO-) in EtOH/HEPES solution (1/99, V/V, pH = 7.4, nearly 100% aqueous solution). Sensor DTB exhibited well specificity, high sensitivity and rapidity (<1 min) for ClO- with a detection limit of 25 nM. Sensor DTB features remarkable color changes and significant fluorescence turn-on response (ca. 45 fold) after treating with CIO . Comprehensive analyses by H-1 NMR, TLC, FTIR, HRMS, UV-vis, fluorescence and DFT illustrated that ClO- reacted with the C=C bond of DTB, generating fluorophore 2T-CHO, leading to strong blue fluorescence. Interestingly, DTB loaded colorimetric test strips were established for rapid and real-time visual detection of ClO-. Furthermore, the DTB was successfully applied to quantitatively and sensitively detect ClO- in 84 disinfectant, bio-fluids (human serum and urine) and actual water samples. Importantly, the biocompatible DTB has been employed for visualizing and bioimaging ClO- in mung bean sprouts, Arabidopsis, live cells and zebrafish. These investigations demonstrate that DTB has great potentials for detecting ClO- in various biosystems and environments. This work would offer a new idea for developing multifunctional sensors with better performance for chemo/biosensors.

Automated summary

A new ICT type chemosensor DTB with D-pi-A structure has been synthesized and demonstrated to have high sensitivity and specificity for detecting hypochlorite (ClO-). DTB can rapidly detect ClO- through colorimetric and fluorometric dual signaling, and has been successfully applied in various biological samples and environments. This research offers a new idea for developing better-performing chemo/biosensors.