TY - JOUR
T1 - Determination of Cu2+ in drinking water using a hydroxyjulolidine-dihydroperimidine colorimetric sensor
AU - Fanna, Daniel J.
AU - Lima, Luís M. P.
AU - Craze, Alexander R.
AU - Trinchi, Adrian
AU - Wei, Gang
AU - Jason K. Reynolds, Jason K.
AU - Li, Feng
PY - 2019
Y1 - 2019
N2 - A new and highly efficient colorimetric Cu2+ chemosensor HL, synthesized by condensation between 8-hydroxyjulolidine-9-carboxaldehyde and 1,8-diaminonaphthalene, has been rationally designed and thoroughly studied. In a buffered aqueous methanol mixture, interactions between HL and Cu2+ produce an intense visible band at 421 nm, considerably red-shifted (~ 100 nm) from the peak maxima of HL (320 nm). Absorbance spectrophotometry experiments pointed to an exceptional 2.3 nM limit of detection (LoD) calculated from the ratiometric response upon Cu2+ binding. Furthermore, without the aid of instrumentation an impressive 0.5 µM LoD is possible by naked-eye observations, far below the 31.5 µM (2 mg/L) guidelines for drinking water established by the World Health Organization. Spectrophotometric pH titrations allowed the determination of the equilibrium constants and speciation plots for the formation of the various chemical species of HL in the absence and presence of Cu2+, with only mononuclear complexes being found. Additional studies highlighted the selectivity of HL to Cu2+ when in the presence of other metal ions, and a 1:1 (M:L) binding stoichiometry has also been confirmed with results from Cu2+ titrations, Job’s plot and ESI-HRMS in good agreement. The Cu2+ sensing mechanism was also found to be reversible by cycling with H2Na2EDTA.
AB - A new and highly efficient colorimetric Cu2+ chemosensor HL, synthesized by condensation between 8-hydroxyjulolidine-9-carboxaldehyde and 1,8-diaminonaphthalene, has been rationally designed and thoroughly studied. In a buffered aqueous methanol mixture, interactions between HL and Cu2+ produce an intense visible band at 421 nm, considerably red-shifted (~ 100 nm) from the peak maxima of HL (320 nm). Absorbance spectrophotometry experiments pointed to an exceptional 2.3 nM limit of detection (LoD) calculated from the ratiometric response upon Cu2+ binding. Furthermore, without the aid of instrumentation an impressive 0.5 µM LoD is possible by naked-eye observations, far below the 31.5 µM (2 mg/L) guidelines for drinking water established by the World Health Organization. Spectrophotometric pH titrations allowed the determination of the equilibrium constants and speciation plots for the formation of the various chemical species of HL in the absence and presence of Cu2+, with only mononuclear complexes being found. Additional studies highlighted the selectivity of HL to Cu2+ when in the presence of other metal ions, and a 1:1 (M:L) binding stoichiometry has also been confirmed with results from Cu2+ titrations, Job’s plot and ESI-HRMS in good agreement. The Cu2+ sensing mechanism was also found to be reversible by cycling with H2Na2EDTA.
KW - analysis
KW - chemical reactions
KW - colorimetric analysis
KW - drinking water
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:48753
U2 - 10.1007/s10847-018-0862-5
DO - 10.1007/s10847-018-0862-5
M3 - Article
SN - 1388-3127
VL - 94
SP - 141
EP - 154
JO - Journal of Inclusion Phenomena and Macrocyclic Chemistry
JF - Journal of Inclusion Phenomena and Macrocyclic Chemistry
IS - 45385
ER -