The luminescence inner filter effect of Mn2+-doped (ZnS)2·octylamine inorganic/organic hybrid thin films and their sensor application for environmental contaminants

Abstract

The II–VI group/monoamine hybrid was a novel inorganic/organic (I/O) layered structure and it exhibited a strong quantum confinement effect and well-defined Mn²⁺-doped luminescence, which was imperative and valuable academically for its application. In this work, the pure and well-crystalline (ZnS:Mn)₂·oa (oa = octylamine) hybrid was prepared by solvothermal synthesis and its thin films were fabricated by the drop-casting method. The 5 at% Mn²⁺-doped hybrid exhibited a strong Mn²⁺ luminescence at 597 nm with a 300 nm excitation. The inner filter effect (IFE) for this luminescence was investigated and verified by detecting three selected environmental contaminant species: n-butyl xanthate (BX), crystal violet (CV), and reaction black 5 (RB5), which indicated that this hybrid thin film had a good luminescence IFE-based linear response for the μM species solution. Furthermore, the 597 nm luminescence remained intact for the solution with a pH from 4 to 10 and the hydrophobicity of the hybrid thin film was favorable for its rapid and multiple IFE-based detection. Therefore, this hybrid thin film is a competitive candidate for the new-generational fluorescence sensors to probe the occurrence of these environmental contaminants.