TY - JOUR
T1 - New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative
AU - Pina-Luis, Georgina
AU - Martínez-Quiroz, Marisela
AU - Ochoa-Terán, Adrián
AU - Santacruz-Ortega, Hisila
AU - Mendez-Valenzuela, Eduardo
PY - 2013/2
Y1 - 2013/2
N2 - This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb2+ ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV-visible and fluorescence spectroscopy. Compounds 1(a-d) with different length alkyl linkers (CH 2)n (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5-8) and was only slightly influenced by the addition of metal ions in CH3CN solutions. However, derivative 1e with amino-containing spacer (CH2-NH-CH2) showed excimer emission in aqueous solution, a wide response to pH (2.5-9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li +, Na+, K+, Cs+, Ca2+, Mg2+, Ba2+, Cu2+, Pb2+, Ni 2+, Zn2+ and Cd2+. The coordination chemistry of these complexes was studied by UV-Vis, fluorescence and 1H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb2+ ions in the presence of the metals ions mentioned in CH 3CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb2+ ions, results in less than ±5% fluorescence intensity changes. Linear calibration up to 1×10-5 M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0×10-8 M.
AB - This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb2+ ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV-visible and fluorescence spectroscopy. Compounds 1(a-d) with different length alkyl linkers (CH 2)n (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5-8) and was only slightly influenced by the addition of metal ions in CH3CN solutions. However, derivative 1e with amino-containing spacer (CH2-NH-CH2) showed excimer emission in aqueous solution, a wide response to pH (2.5-9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li +, Na+, K+, Cs+, Ca2+, Mg2+, Ba2+, Cu2+, Pb2+, Ni 2+, Zn2+ and Cd2+. The coordination chemistry of these complexes was studied by UV-Vis, fluorescence and 1H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb2+ ions in the presence of the metals ions mentioned in CH 3CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb2+ ions, results in less than ±5% fluorescence intensity changes. Linear calibration up to 1×10-5 M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0×10-8 M.
KW - Bis(naphtalimides)
KW - Dual emission
KW - Excimer
KW - PET
KW - Pb sensor
KW - pH sensor
UR - http://www.scopus.com/inward/record.url?scp=84869500327&partnerID=8YFLogxK
U2 - 10.1016/j.jlumin.2012.07.002
DO - 10.1016/j.jlumin.2012.07.002
M3 - Artículo
SN - 0022-2313
VL - 134
SP - 729
EP - 738
JO - Journal of Luminescence
JF - Journal of Luminescence
ER -