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

In this article, Mn 2+ -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 K 2 S 2 O 8 as oxidizing agents led to decrease in PL emission intensity due to Mn 2+ ( 4 T 1 – 6 A 1 ), and subsequent addition of NaBH 4 into K 2 S 2 O 8 -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.