title: A sensitive and selective mercury(II) sensor based on amplified fluorescence quenching in a conjugated polyelectrolyte/spiro-cyclic rhodamine system.
abstract: A novel fluorescence-based sensor for mercury(II) ion is described consisting of a water-soluble, anionic-conjugated polyelectrolyte (CPE) and spiro-cyclic rhodamine derivative (1). A solution containing the CPE (0.1 × 10(-6) M repeat unit concentration) and 1 (1 × 10(-6) M concentration) in aqueous solution exhibits a sensitive and selective turn-off fluorescence response to Hg(II). The Stern-Volmer quenching constant for quenching of the fluorescence of the system by Hg(II) is ≈1.5 × 10(7) M(-1) , and Hg(II) can be sensed with a detection limit <10 × 10(-9) M. A mechanism for the sensor response is proposed and it consists of efficient and selective complex formation between 1 and Hg(II), along with a very high association between the 1-Hg(II) complex and the anionic CPE.
authors.affiliation: Department of Chemistry, Center for Macromolecular Science and Engineering, University of Florida, Gainesville, FL 32611-7200, USA.
authors.forename: Seoung Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Anand
authors.initials: A
authors.lastname: Parthasarathy
authors.forename: Kirk S
authors.initials: KS
authors.lastname: Schanze
mesh_terms: D015374:Biosensing Techniques; D005453:Fluorescence; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D011108:Polymers; D012235:Rhodamines; D012996:Solutions; D008628:Mercury