Novel pyrene containing monomeric and dimeric supramolecular AIEE active nano-probes utilized in selective "off-on" trivalent metal and highly acidic pH sensing with live cell applications

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2016-03, Vol.4 (1), p.256-271
• Main Authors: Shellaiah, Muthaiah, Simon, Turibius, Srinivasadesikan, Venkatesan, Lin, Chein-Ming, Sun, Kien Wen, Ko, Fu-Hsiang, Lin, Ming-Chang, Lin, Hong-Cheu
• Format: Article
• Language: English
• Subjects: Detection; Fluorescence; Imaging; Materials selection; Metal ions; Photoluminescence; Sensors; Transmission electron microscopy
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c5tc03738g

Two novel pyrene containing monomeric and dimeric Schiff base derivatives PCS1 and PCS2 have been synthesized via one-pot reaction and their nano-J-type aggregation induced emission enhancement (AIEE) was well demonstrated using UV-Vis/PL, transmission electron microscopy (TEM), dynamic light scattering (DLS), time resolved photoluminescence (TRPL), and live cell imaging studies. In contrast to PCS2 , PCS1 in CH 3 CN exhibits fluorescence "off-on" sensor selectivity towards transition trivalent metal ions (Fe 3+ , Cr 3+ and Al 3+ ) among other metals, via PET inhibition with excimer PCS1-PCS1* formation. The 2 : 1 stoichiometry of PCS1 M 3+ (M = Fe/Cr/Al) sensor complexes was calculated from Job's plots based on their PL titrations. In addition, the binding sites of PCS1 M 3+ sensor complexes were well recognised from the 1 H NMR titrations and supported by ESI(+ve) mass and FTIR analysis. Additionally, fluorescence reversibilities of PCS1 M 3+ were observed via consequent addition of M 3+ ions and PMDTA, respectively. Furthermore, the detection limits (LODs) and the association constant ( K a ) values of PCS1 M 3+ complexes were calculated using standard deviation and linear fittings. Likewise, quantum yield ( Φ ) measurements, TEM analysis, determination of the effect of pH, density functional theory (DFT) and time resolved photoluminescence (TRPL) studies were performed for the PCS1 M 3+ sensor complexes. More importantly, confocal fluorescence microscopy imaging of Raw264.7 cells showed that PCS1 could be used as an effective fluorescent probe for detecting transition trivalent metal ions (Fe 3+ , Cr 3+ , and Al 3+ ) in living cells. Impressively, both PCS1 and PCS2 showed "off-on" sensing at highly acidic pH values (1-3) with live cell applications. Novel pyrene based derivatives PCS1 / PCS2 with AIEE were reported as trivalent and pH 1-3 sensors using live cell imaging.