Retracted Article: Facile fabrication of water-dispersible AgInS₂ quantum dots and mesoporous AgInS₂ nanospheres with visible photoluminescence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 AgInS 2 quantum dots (QDs) with near-infrared (NIR) emission was developed. In the presence of polyethylenimine, the as-prepared AgInS 2 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 AgInS 2 nanospheres. Experimental results confirmed that the AgInS 2 nanospheres exhibited a mesoporous structure and consisted of repeated units of AgInS 2 QDs. The mesoporous AgInS 2 nanospheres had photoluminescence (PL) in the visible region that was different from that of the original AgInS 2 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 AgInS 2 nanospheres for biomedical application, especially serving as novel nanoprobes for in vitro and in vivo PL imaging.

Cathode–Anode Spatial Division Photoelectrochemical Platform Based on a One-Step DNA Walker for Monitoring of miRNA-21

“…Aiming at obtaining and confirming the bulk structure information of AgInS 2 NPs, XRD characterization was performed. As displayed in Figure C, the diffraction peaks of AgInS 2 NPs highly corresponded to JCPDS PDF 25-1328 and were consistent with the previous study, which were a typical orthorhombic system . X-ray photoelectron spectroscopy (XPS) was adopted to qualitatively analyze the elemental composition of AgInS 2 NPs.…”

“…In order to explore the optical properties of AgInS 2 NPs, ultraviolet−visible (UV−vis) absorption and Fourier transform infrared (FTIR) spectroscopy were carried out. As shown in Figure S2A, AgInS 2 NPs exhibited a characteristic acromion absorption peak at ∼590 nm 39 and the wide absorption spectrum of 400 to 800 nm, making it possible to use almost the entire visible-light region. The peaks located at 3420, 1715, and 1390 cm −1 could be assigned to the infrared stretching vibration absorption of O−H, CO, and C−O, 16 indicating the attachment of carboxyl groups on AgInS 2 NPs, which was beneficial to the subsequent biological chain connection (Figure S2B).…”

Passivating effect of ternary alloyed AgZnSe shell layer on the structural and luminescent properties of CdS quantum dots

“…Another strategy which has drawn significant interest in improving the PL QY of binary core QDs is to coat the surface with an alloyed ternary shell layer. Alloyed QDs (ABxC1-x) have become important in mainstream nanoscale optical engineering due to the added degree of freedom in tuning the exciton energy for either extended PL emission range or improved optical properties [29][30][31][32]. The coating of an alloyed ternary shell around binary core QDs to improve the PL efficiency has mostly been reported for CdSe-based QDs [33,34] with rare reports for CdS-based QDs [13].…”

One-Step Synthesis of Water-Soluble Quantum Dots from Ag2S and AgInS2 QDs

“…18 How to clarify the toxicity mechanism and solve the toxicity problem of these kinds of binary QDs will be important subjects for further study. Compared with binary QDs, new ternary QDs (e.g., AgInS 2 (AIS) 19 and CuInS 2 20 ) of the class IA−IIIA−VIA family avoid these toxic metals.…”