title: Ratiometric fluorescent ion detection in water with high sensitivity via aggregation-mediated fluorescence resonance energy transfer using a conjugated polyelectrolyte as an optical platform.
abstract: A cationic conjugated polyelectrolyte was designed and synthesized based on poly(fluorene-co-phenylene) containing 5 mol% benzothiadiazole (BT) as a low energy trap and 15-crown-5 as a recognizing group for potassium ions. A potassium ion can form a sandwich-type 2:1 Lewis acid-based complex with 15-crown-5, to cause the intermolecular aggregation of polymers. This facilitates inter-chain fluorescence resonance energy transfer (FRET) to a low-energy BT segment, resulting in fluorescent signal amplification, even at dilute analyte concentrations. Highly sensitive and selective detection of K(+) ions was demonstrated in water. The linear response of ratiometric fluorescent signal as a function of [K(+) ] allows K(+) quantification in a range of nanomolar concentrations with a detection limit of ≈0.7 × 10(-9) M.
authors: Department of Nanofusion Technology, Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang 627-706, Republic of Korea.
authors: Van Sang
authors: VS
authors: Le
authors: Boram
authors: B
authors: Kim
authors: Wonho
authors: W
authors: Lee
authors: Ji-Eun
authors: JE
authors: Jeong
authors: Renqiang
authors: R
authors: Yang
authors: Han Young
authors: HY
authors: Woo
mesh_terms: D002414:Cations, Monovalent; D043844:Crown Ethers / Q000737:chemistry; D005449:Fluorenes / Q000138:chemical synthesis* / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011188:Potassium / Q000032:analysis; D013830:Thiadiazoles / Q000138:chemical synthesis* / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D002414:Cations, Monovalent; D043844:Crown Ethers; D005449:Fluorenes; D011108:Polymers; D013830:Thiadiazoles; D014867:Water; C042148:15-crown-5; D011188:Potassium