Retracted Article: Facile fabrication of water-dispersible AgInS2 quantum dots and mesoporous AgInS2 nanospheres with visible photoluminescence

Abstract

A facile one-step method for preparing water-dispersible carboxylic acid-terminated AgInS₂ quantum dots (QDs) with near-infrared (NIR) emission was developed. In the presence of polyethylenimine, the as-prepared AgInS₂ QDs gathered together to form QDs-self-assemblies, followed by centrifugating to obtain QDs aggregates. After that, the resulting QDs aggregates were calcined at elevated temperature to yield AgInS₂ nanospheres. Experimental results confirmed that the AgInS₂ nanospheres exhibited a mesoporous structure and consisted of repeated units of AgInS₂ QDs. The mesoporous AgInS₂ nanospheres had photoluminescence (PL) in the visible region that was different from that of the original AgInS₂ QDs emitted in the NIR region. High PL stability and low cytotoxicity of the nanospheres were verified experimentally. These results further revealed the potential of mesoporous AgInS₂ nanospheres for biomedical application, especially serving as novel nanoprobes for in vitro and in vivo PL imaging.