Photoluminescence-enhanced CdTe quantum dots by hyperbranched poly(amidoamine)s functionalization

Abstract

A new strategy using hyperbranched poly(amidoamine)s to functionalize CdTe quantum dots (QDs) has been described. Hyperbranched poly(amidoamine)s with amine terminals (HP-EDAMA1) were synthesized by one-pot polymerization via the coupled-monomer method and subsequently used to functionalize preformed CdTe QDs. Quite different from previous studies in which the photoluminescence of QDs was quenched by further functionalization with tailored ligands, the quantum yield of CdTe/HP-EDAMA1 nanocomposites was 2 times that of pure CdTe QDs without modification. With this versatile method, the photoluminescence quenching of QDs in the modification process by matrix materials can be effectively solved and new QDs/hyperbranched polymer nanocomposites with potential applications in biomedicine might be offered.

Highly Enhanced Fluorescence of CdSeTe Quantum Dots Coated with Polyanilines via In-Situ Polymerization and Cell Imaging Application

“…Up to now, some methods of decorating QDs with hydrophilic polymer have been developed. Polyethylene glycol (PEG), polyethylene glycol-phosphatidyl ethanolamine copolymer (PEG–PE) and poly­(methyl methacrylate) (PMMA) have been decorated onto QDs to improve their stability and biocompatibility, − and polyamide amine (PAMAM) has been grafted onto QDs to functionalize the initial QDs. − The fluorescence intensity and the quantum yields of the QDs prepared by some of the methods have been improved to a certain degree (∼2 times), , but in most cases the fluorescence intensity of the QDs coated with such polymers has not been improved or even decreased, or the largely increased particle size resulted in some restrictions for their applications. Conducting polymers, such as polyaniline (PAN), polypyrrole (PPY) and polythiophene (PTH) have aroused great interest because of their attractive properties, for example, conductivity, mechanical flexibility, and biocompatibility. − The band gap of conducting polymers can be adjusted by controlling their degree of polymerization, rendering them the properties of a semiconductor.…”

Latest Trends in Lateral Flow Immunoassay (LFIA) Detection Labels and Conjugation Process

“…One study reported using an innovative method of functionalization, with hyperbranched poly (amidoamine)s (HP-EDAMA), which in contrast to previously described methods appears to enhance the photoluminescent properties of the QDs by as much as 2 times. The nanocomposites were prepared using a simple procedure, which involves the preparation of a CdTe solution and adding it to a solution of (HP-EDAMA), drop wise, under vigorous stirring ( Shi et al, 2013 ). CdTe with thioglycolic acid (TGA) and mercapto-acetohydrazide (TGH), synthetized by the hydrothermal method, were functionalized with PEG by forming a hydrazone chain via the reaction of aldehyde and hydrazine ( Du et al, 2019 ).…”

Dendronised Polymers as Templates for In Situ Quantum Dot Synthesis

“…[35,36] In previous studies, thiol-capped CdTe(S) QDs were synthesised by using 3mercaptopropionic acid (MPA) or L-cysteine, which electrostatically interacted with different dendrimer generations to produce luminescent multifunctional nanohybrids. [37,38] In addition, thiolated PAMAM dendrimers have been previously used as coating ligands for CdSe/ZnSe QDs. However, the thiolated PAMAM dendrimers were used to replace trioctylphosphine oxide (TOPO) ligands on the surface of CdSe/ZnSe QDs by a ligand exchange procedure.…”