A novel UV-visible chemosensor based on the 8-hydroxyquinoline derivative for copper ion detection

Abstract

A novel UV-visible chemosensor, 4-methyl-2-((quinolinyl-8-amino)methyl)phenol (MQAMP), was designed and synthesized. The spectral properties of its free and Cu²⁺-coordinated forms were characterized. Under the optimized conditions, MQAMP showed selective and sensitive sensing for copper ions in an ethanol solution. The binding of Cu²⁺ to MQAMP caused a marked enhancement of the absorbance, and an about 100 nm red-shift of the maximum absorption wavelength. Other ions including Mo⁶⁺, Li⁺, Cs⁺, As³⁺, Ca²⁺, Na⁺, Cd²⁺, K⁺, Mg²⁺, Pt²⁺, Sr²⁺, Ba²⁺, Al³⁺, Cr⁶⁺, Be²⁺, Fe³⁺, Ni²⁺, F⁻, CH₃COO⁻, SO₄²⁻, NO₃⁻, Cl⁻, CO₃²⁻, and SO₃²⁻ displayed no significant interference in this detection of Cu²⁺. The chemosensor exhibited a dynamic response range for Cu²⁺ from 1.0 × 10⁻⁶ to 1.0 × 10⁻⁵ mol L⁻¹ with a detection limit of 1.1 × 10⁻⁷ mol L⁻¹ (3σ).