A new fluorescence probe for detection of Cu⁺² in blood samples: Circuit logic gate

A Fluorescence probe was designed based on 8-hydroxyquinoline chitosan silica precursor (HQCS) for selective detection of Al³⁺, Cu²⁺. The HQCS has no observable fluorescence signal, but after the addition of Al³⁺, a huge fluorescence signal appeared, and the selective quenching was absorbed after the addition of Cu²⁺. The effect of other different cations, including Cu²⁺, Mg²⁺, Ca²⁺, Pb²⁺, Zn²⁺, Hg²⁺, Ag⁺, Fe^3+, and K⁺ was studied. The addition of Cu²⁺ to the probe (HQCSAL) decreased the fluorescence very repeatable, and the variation of the fluorescence vs. Cu²⁺ was monotonic and linear. Therefore, the prepared probe was used to determine Cu²⁺ ions in real samples. The mechanism of fluorescence variation by adding cations to the probe solution was studied using the Stern-Volmer equation. Under the optimum conditions, the linear range and detection limit were 3.5-31 μM and 1 μM, respectively. The probe accuracy on the copper determination in the blood and tap waters was comparable to the ICP-OES results. The circuit logic gate mimic was designed for the fluorescence behavior of the probe constituents.