Fluorescent Guar Gum- g -Terpolymer via In Situ Acrylamido-Acid Fluorophore-Monomer in Cell Imaging, Pb(II) Sensor, and Security Ink.

The nonconventional purely aliphatic scalable and reusable fluorescent guar gum (GRGM)- grafted -acrylic acid- co -3-( N -isopropylacrylamido)propanoic acid (NIPAPA)- co - N -isopropylacrylamide (GRGM- grafted - 1 , i.e., 2 ), was synthesized via grafting of the optimum amount of GRGM and N- H functionalized in situ protrusion of acrylamido-acid fluorophore-monomer, i.e., NIPAPA, in multi C-C/N-C/O-C coupled solution polymerization of two non-emissive monomers in water. The intrinsically fluorescent noncytotoxic 2 envisaged the excellent potentials in sensing and removal of Pb(II), security ink, logic function, and imaging of both cancer and normal cells. The emission intensities of 2 elevated in concentrated solutions and solid state because of concentration-enhanced emission and aggregation-induced enhanced emission (AIEE) characteristics of 2 . Additionally, the emission efficiency of 2 elevated considerably with increasing GRGM contents and temperatures. The structure of 2 , in situ attached fluorophore-monomer, AIEE, cell-imaging ability, and the superadsorption mechanism were studied employing 1 H/ 13 C NMR, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, atomic absorption spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, dynamic light scattering, high-resolution transmission electron microscopy, fluorescence imaging, and fluorescence lifetime, along with measuring isotherms, kinetics, and thermodynamic parameters. The location, geometries, and electronic-structures of fluorophore, along with absorption and emission properties, of 2 were explored via density functional theory (DFT), time-dependent DFT, and natural transition orbital analyses. In solution, cyan light-emitting 2 envisaged an average 1.22 ns lifetime in CHCl 3 . The limit of detection and the maximum adsorption capacity were 2.94 × 10 -7 M and 1100.25 mg g -1 at pH 7.0, 303 K, and 1000 ppm, respectively.