Ruiming Chen,Shu Xing,Tingting Hu,Yiming Li,Jianbin Chen,Qingfen Niu,Tianduo Li
A new ICT type D-π-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 ClO − . Comprehensive analyses by 1 H 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.
A displacement-based electrochemical dual-signal kanamycin (KAN) aptamer sensing method was developed using a theory-driven approach, with methylene violet (MV) and toluidine blue (TB) as dual-signal labels. The binding poses were elucidated using molecular dynamics simulation (MDS) while simulating the kinetic evolution process of the displacement reaction. The binding system’s binding free energy (ΔG) was calculated using the g_mmpbsa algorithm. The MDS results guided the sensor fabrication process, and the sensing analytical performance was subsequently investigated. The study demonstrated the thermodynamic feasibility of the displacement reaction, with ΔG values of −3079 ± 122, −955 ± 78, and −879 ± 46 KJ·mol −1 for the three binding systems, respectively. The simulated kinetic evolution process aligned with the displacement reaction’s behavior characteristics, primarily driven by electrostatic attraction, thereby deciphering the sensor’s signaling mechanism. Under optimized conditions, the sensor exhibited a dual-signal response, a detection limit of 0.17 μM, a linear range of 1.0 μM to 2.0 mM, a response equilibrium time of ∼ 45 min., and a discriminated selectivity clarified by the MDS. The mutual support between MDS and experimental results establishes a communication bridge between simulation and experimentation, guiding the sensor fabrication direction and providing a methodological basis and new research example for aptamer-based sensor designs.
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