Fluorescent detection of lead in environmental water and urine samples using enzyme mimics of catechin-synthesized Au nanoparticles.
A facile, cost-effective, and sensitive fluorescent method for Pb²⁺ ion detection had been developed using catechin synthesized gold nanoparticles (C-Au NPs). The Pb-catechin complexes and Pb-Au alloys that formed on the C-Au NPs surfaces allowed NPs to exhibit peroxidase-mimicking catalytic activity in the H₂O₂-mediated oxidation of Amplex UltraRed (AUR). In 5 mM Tris-acetate buffers at pH 7.0, the H₂O₂-AUR-C-Au NP probe was highly selective (>100-fold) for Pb²⁺ ions in the presence of other tested metal ions (K⁺, Ag⁺, Na⁺, Cd²⁺, Ni²⁺, Ca²⁺, Hg²⁺, Sr²⁺, Co²⁺, Cu²⁺, Ba²⁺, Fe²⁺, Mg²⁺, Cr³⁺, and Fe³⁺ ions). The fluorescence intensity (excitation/emission maxima ∼540/588 nm) of the AUR product was proportional to the concentration of Pb²⁺ ions in the range of 10 nM-1.0 μM with a linear correlation (R² = 0.99). The H₂O₂-AUR-C-Au NP probe detected Pb²⁺ ions with a limit of detection (signal-to-noise ratio: 3) of 1.5 nM. The practicality of the H₂O₂-AUR-C-Au NP probe was validated for the determination of Pb²⁺ ion concentration in environmental water and urine samples, demonstrating its advantages of simplicity, selectivity, and sensitivity.
Department of Chemistry, National Changhua University of Education, Changhua, Taiwan.
Yan-Shiuan
YS
Wu
Fan-Feng
FF
Huang
Yang-Wei
YW
Lin
D002392:Catechin / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007854:Lead / Q000032:analysis* / Q000652:urine; D053768:Metal Nanoparticles; D018716:Molecular Mimicry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013054:Spectrophotometry, Atomic; D013056:Spectrophotometry, Ultraviolet
D007854:Lead; D006046:Gold; D002392:Catechin