Acetyl acetonate-stabilized Mn2+:CdS quantum dots: Aqueous synthesis and reversible fluorescence tuned by redox reaction

In this article, Mn2+-doped CdS quantum dots (QDs) were synthesized using acetyl acetonate as a stabilizing agent in aqueous media. The as-prepared QDs exhibited reversible photoluminescence (PL) via partial oxidation of the emitting Mn species and subsequent reduction of the oxidized form. Treatment of the QDs with K2S2O8 as oxidizing agents led to decrease in PL emission intensity due to Mn2+ (4T1–6A1), and subsequent addition of NaBH4 into K2S2O8-treated QDs resulted in PL recovery. The PL changes of the QDs were almost fully reversible after undergoing repeated oxidizing–reducing cycles, indicating their potential applications as versatile PL probes and labels for biological assays, imaging of cells and tissues in vivo, especially for the detection of redox reactions.

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► Water-soluble Mn2+-doped CdS quantum dots (QDs) were synthesized using acetyl acetonate as capping agents.
► Addition of K2S2O8 induced fluorescent decrease of the QDs.
► Subsequent addition of NaBH4 caused fluorescence recovery.
► The fluorescence changes are almost fully reversible.