title: Silicon Quantum Dot-Based Fluorescence Turn-On Metal Ion Sensors in Live Cells.
abstract: Multiple sensor systems are designed by varying aza-crown ether moiety in silicon quantum dots (SiQDs) for detecting individual Mg(2+), Ca(2+), and Mn(2+) metal ions with significant selectivity and sensitivity. The detection limit of Mg(2+), Ca(2+), and Mn(2+) can reach 1.81, 3.15, and 0.47 μM, respectively. Upon excitation of the SiQDs which are coordinated with aza-crown ethers, the photoinduced electron transfer (PET) takes place from aza-crown ether moiety to the valence band of SiQDs core such that the reduced probability of electron-hole recombination may diminish the subsequent fluorescence. The fluorescence suppression caused by such PET effect will be relieved after selective metal ion is added. The charge-electron binding force between the metal ion and aza-crown ether hinders the PET and thereby restores the fluorescence of SiQDs. The design of sensor system is based on the fluorescence "turn-on" of SiQDs while in search of the appropriate metal ion. For practical application, the sensing capabilities of metal ions in the live cells are performed and the confocal image results reveal their promising applicability as an effective and nontoxic metal ion sensor.
authors.affiliation: Department of Chemistry, National Taiwan University , Taipei 106, Taiwan.|Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Dhenadhayalan
authors.affiliation: Department of Chemistry, National Taiwan University , Taipei 106, Taiwan.|Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.
authors.forename: Hsin-Lung
authors.initials: HL
authors.lastname: Lee
authors.affiliation: Department of Chemistry, National Taiwan University , Taipei 106, Taiwan.|Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.
authors.forename: Kanchan
authors.initials: K
authors.lastname: Yadav
authors.affiliation: Department of Chemistry, National Taiwan University , Taipei 106, Taiwan.|Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.
authors.forename: King-Chuen
authors.initials: KC
authors.lastname: Lin
authors.affiliation: Department of Chemistry, National Dong Hwa University , Shoufeng, Hualien 974, Taiwan.
authors.forename: Yih-Tyng
authors.initials: YT
authors.lastname: Lin
authors.affiliation: Department of Chemistry, National Dong Hwa University , Shoufeng, Hualien 974, Taiwan.
authors.forename: A H H
authors.initials: AH
authors.lastname: Chang
mesh_terms: D002470:Cell Survival; D043844:Crown Ethers; D007477:Ions; D008670:Metals; D045663:Quantum Dots; D012825:Silicon
chemical_list: D043844:Crown Ethers; D007477:Ions; D008670:Metals; D012825:Silicon
keywords: aza-crown ether; bioimaging; metal ion; photoinduced electron transfer; sensors; silicon quantum dots