title: Fluorescence sensor using a molecularly imprinted polymer as a recognition receptor for the detection of aluminium ions in aqueous media.
abstract: This paper describes the investigation of a molecularly imprinted polymer (MIP) as a sensing receptor for Al(3+) ion detection by using an optical approach. Al(3+) ion was adopted as the template molecule and 8-hydroxyquinoline sulfonic acid ligand as the fluorescence tag. The polymer was synthesised using acrylamide as monomer, 2-hydroxyethyl methacrylate as co-monomer and ethylene glycol dimethracylate as cross-linker. The free radical polymerisation was performed in methanol and initiated by 2,2'-azobisisobutyronitrile at 70 degrees C. The imprinted polymer was fluorometrically characterised using a fibre optic attachment in a self-designed flow-cell. NaF was used to leach the Al(3+) ion from the MIP. The optimum pH for the rebinding of Al(3+) ion with the leached polymer was found to be pH 5 and the fluorescence response was found to be stable within the buffer strength range of 0.05-0.10 M. The fluorescence intensity during Al(3+) ion rebinding was inversely dependent on temperature, and a low interference response (<3%) toward metal ions except for Cu(2+) and Zn(2+) ions was observed. The polymer rebinding repeatability study conducted over 9 cycles with Al(3+) ion (0.8 x 10(-4) M) was found to give an RSD value of 2.82% with a standard deviation of 0.53. The dynamic range of the system was found to be linear up to 1.0 x 10(-4) M Al(3+) ion with a limit of detection of 3.62 microM.
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M60 1QD, UK.
authors.forename: Sing Muk
authors.initials: SM
authors.lastname: Ng
authors.forename: R
authors.initials: R
authors.lastname: Narayanaswamy
mesh_terms: D000535:Aluminum / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000032:analysis; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000032:analysis* / Q000138:chemical synthesis; D009994:Osmolar Concentration; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D007477:Ions; D009942:Organometallic Compounds; D011108:Polymers; D014867:Water; D000535:Aluminum