title: From Binary Cu2S to ternary Cu-In-S and quaternary Cu-In-Zn-S nanocrystals with tunable composition via partial cation exchange.
abstract: We present an approach for the synthesis of ternary copper indium sulfide (CIS) and quaternary copper indium zinc sulfide (CIZS) nanocrystals (NCs) by means of partial cation exchange with In(3+) and Zn(2+). The approach consists of a sequential three-step synthesis: first, binary Cu2S NCs were synthesized, followed by the homogeneous incorporation of In(3+) by an in situ partial cation-exchange reaction, leading to CIS NCs. In the last step, a second partial exchange was performed where Zn(2+) partially replaced the Cu(+) and In(3+) cations at the surface, creating a ZnS-rich shell with the preservation of the size and shape. By careful tuning reaction parameters (growth and exchange times as well as the initial Cu(+):In(3+):Zn(2+) ratios), control over both the size and composition was achieved. This led to a broad tuning of photoluminescence of the final CIZS NCs, ranging from 880 to 1030 nm without altering the NCs size. Cytotoxicity tests confirmed the biocompatibility of the synthesized CIZS NCs, which opens up opportunities for their application as near-infrared fluorescent markers in the biomedical field.
authors.affiliation: Department of Nanochemistry, Istituto Italiano di Tecnologia , via Morego, 30, 16163 Genova, Italy.
authors.forename: Quinten A
authors.initials: QA
authors.lastname: Akkerman
authors.forename: Alessandro
authors.initials: A
authors.lastname: Genovese
authors.forename: Chandramohan
authors.initials: C
authors.lastname: George
authors.forename: Mirko
authors.initials: M
authors.lastname: Prato
authors.forename: Iwan
authors.initials: I
authors.lastname: Moreels
authors.forename: Alberto
authors.initials: A
authors.lastname: Casu
authors.forename: Sergio
authors.initials: S
authors.lastname: Marras
authors.forename: Alberto
authors.initials: A
authors.lastname: Curcio
authors.forename: Alice
authors.initials: A
authors.lastname: Scarpellini
authors.forename: Teresa
authors.initials: T
authors.lastname: Pellegrino
authors.forename: Liberato
authors.initials: L
authors.lastname: Manna
authors.forename: Vladimir
authors.initials: V
authors.lastname: Lesnyak
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D006801:Humans; D007204:Indium / Q000737:chemistry*; D007474:Ion Exchange; D007624:KB Cells; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D036103:Nanotechnology; D055620:Optical Phenomena; D010316:Particle Size; D013440:Sulfides / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D013440:Sulfides; D007204:Indium; C099343:cuprous sulfide; D013455:Sulfur; D003300:Copper; D015032:Zinc
keywords: Stokes shift engineering; alloys; cation exchange; copper indium sulfide; copper indium zinc sulfide; copper sulfide; cyclic voltammetry; nanocrystals; photoluminescence