Pyrene-Based AIEE Active Nanoprobe for Zn and Tyrosine Detection Demonstrated by DFT, Bioimaging, and Organic Thin-Film Transistor.

The development of aggregation-induced emission enhancement (AIEE) active nanoprobes without any synthetic complication for solution-state and organic thin-film transistor (OTFT)-based sensory applications is still a challenging task. In this study, the novel pyrene-incorporated Schiff base (5-phenyl-4-((pyren-1-ylmethylene)amino)-4-1,2,4-triazole-3-thiol; ) with an AIEE property was synthesized via a one-pot reaction and was reported for detecting Zn and tyrosine in the solution state and OTFT. In the AIEE studies of (in CHCN) at various water fractions (: 0-97.5%), the existence of -aggregation, crystalline changes, and nanofibers formation was confirmed by ultraviolet absorption/photoluminescence (UV/PL) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic-light scattering (DLS) techniques. Similarly, -based Zn detection and sensory reversibility with tyrosine were demonstrated by UV/PL studies with evidence related to crystalline/nanolevel changes in PXRD, SEM, TEM, AFM, and DLS data. Distinct decay profiles associated with the AIEE and sensory responses of were observed in time-resolved photoluminescence spectra. From the standard deviation and linear fittings of PL titrations, detection limits (LODs) of the Zn with and the tyrosine with -Zn were estimated as 0.79 and 45 nM, respectively. High-resolution mass and H NMR results confirmed 2:1 and 1:1 stoichiometry and binding sites of -Zn- and tyrosine-Zn complexes. Moreover, the values of association constants determined by linear fittings were 4.205 × 10 and 1.73 × 10 M, correspondingly. Optimization via the density functional theory disclosed the binding sites and suppression of twisted intramolecular charge transfer/photoinduced electron transfer (TICT/PET) as well as the involvement of restricted intramolecular rotation in the AIEE and PET "ON-OFF-ON" mechanisms in the Zn and tyrosine sensors. Results from the B16-F10 cellular and zebrafish imaging of AIEE, Zn, and tyrosine sensors further attested the applicability of in biological samples. Finally, the and pentacene-incorporated OTFT devices were fabricated. The devices displayed more than 90% change in drain-source current when reacted with Zn with an LOD of 5.46 μM but showed no response to tyrosine, thereby confirming the reversibility. Moreover, the OTFT devices also demonstrated Zn ion detection in tap water and lake water samples.