Synthesis of Luminescent ZnS Quantum Dots and the Application for Selective Cu²⁺ Probe in Physiological Solution

Abstract

A novel water-soluble luminescent ZnS Quantum Dots (QDs) capped by thiourea have been synthesized in aqueous solution. The thiourea-capped ZnS QDs were used as a fluorescence probe to investigate the luminescence response to physiologically important metal cations in tris-HCl buffer solution. The experiments show that the QDs probe were sensitive to only copper ions and insensitive to other physiologically important cations, such as iron, zinc, sodium, potassium, calcium, magnesium, cobalt, and magnesium ions. The detection limit was found to be 7.3 × 10⁻⁷ M and the quenching effect description was attempted using Stern-Volmer-type equation.

Keywords:

• ZnS
• quantum dots
• probe
• luminescence