Colorimetric and fluorometric chemosensors for selective signaling toward Ca2+ and Mg2+ by aza-crown ether acridinedione-functionalized gold nanoparticles
作者:Ranganathan Velu、Vayalakkavoor T. Ramakrishnan、Perumal Ramamurthy
DOI:10.1016/j.tetlet.2010.06.041
日期:2010.8
The aza-crown ether acridinedione-functionalized gold nanoparticles (ACEADD-GNPs) 6 have been synthesized and investigated as a fluorescent chemosensor for metal ions A blue shift along with an intensity enhancement of emission and color change are observed in the presence of both Ca2+ and Mg2+ ions The enhanced fluorescence intensity is attributed to the photoinduced electron transfer (PET) suppression through space and color change of the suspension from red to blue due to shifted surface plasmon resonance (SPR) with aggregation of nanoparticles by the sandwich complexation (c) 2010 Elsevier Ltd All rights reserved
Selective fluoride ion recognition by a thiourea based receptor linked acridinedione functionalized gold nanoparticles
作者:R. Velu、V.T. Ramakrishnan、P. Ramamurthy
DOI:10.1016/j.jphotochem.2010.10.025
日期:2011.1
The design and synthesis of acridinedione functionalized gold nanoparticles based PET anion sensor 6 is described. The sensor 6 employs simple aromatic thiourea as anion receptors and the fluorophore is the acridinedione moiety, which were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), UV-vis, steady-state and time-resolved fluorescence techniques. Upon selective recognition of F in acetonitrile, the fluorescence emission of 6 was quenched with significant changes in the absorption spectrum. These changes are ascribed due to the hydrogen bonding and deprotonation of the thiourea receptor of ADDTU-GNPs. (C) 2010 Elsevier B.V. All rights reserved.
Metal ion-induced dual fluorescent change for aza-crown ether acridinedione-functionalized gold nanorods and quantum dots
作者:Ranganathan Velu、Nayoun Won、Jungheon Kwag、Sungwook Jung、Jaehyun Hur、Sungjee Kim、Nokyoung Park
DOI:10.1039/c2nj40444c
日期:——
Aza-crown ether acridinedione-functionalized quantum dots (ACEADD-QDs) and aza-crown ether acridinedione-functionalized gold nanorods (ACEADD-GNRs) have been developed as a pair for a fluorescent chemosensor detecting metal ions. The ACEADD-QDs have dual emissions at a visible wavelength of ∼430 nm from the acridinedione dye moiety and at a near-infrared (NIR) wavelength of ∼775 nm from the CdTeSe QDs. In the presence of Ca2+ or Mg2+ ions, the ACEADD-QD and ACEADD-GNR pair can form a sandwich complex mediated by the metal ion. The ACEADD-QD and ACEADD-GNR complex pair shows visible fluorescence enhancement from the acridinedione dye and concurrent fluorescence quenching from the NIR QD. The aza-crown ether complex results in the suppression of photoinduced electron transfer from the aza-crown ether to the acridinedione dye moiety. At the same time, the QD fluorescence can be effectively quenched by the nanometal surface energy transfer from the QD to the GNR. This ACEADD-QD and ACEADD-GNR pair can effectively transduce the selective binding event of crown ethers with metal ions into the simultaneous modulation of the enhancement in dye fluorescence and the quenching of QD emission, which can open a new strategy for ratiometric sensors that are selective and robust against the environment conditions.