Oxidation-triggered aggregation of gold nanoparticles for naked-eye detection of hydrogen peroxide.

Naked-eye detection of H2O2 was realized based on the color change of gold nanoparticles upon aggregation. The removal of polyethylene glycol chains from the nanoparticle surface under H2O2 treatment let to the exposure of inner hydrophobic ligands, causing the nanoparticle aggregation in aqueous medium. This detection system shows a wide dynamic range in the μM scale and a distinguishable limit of 10 μM.

An imine-based approach to prepare amine-functionalized Janus gold nanoparticles.

An imine-based approach was developed to prepare Janus gold nanoparticles (Janus AuNPs) having amine functionality on one patch of the surface and a polyethylene glycol unit on the other. This unique technique features covalent bonding as the force to immobilize AuNPs on the template, enabling direct modification of AuNPs in both water and organic solvents. Colloidal clusters were then obtained via electrostatic assembly of these Janus AuNPs with citrate stabilized AuNPs or AgNPs.

Iron(III)-quantity-dependent aggregation-dispersion conversion of functionalized gold nanoparticles.

Developing gold nanoparticles (AuNPs) with well-designed functionality is highly desirable for boosting the performance and versatility of inorganic-organic hybrid materials. In an attempt to achieve ion recognition with specific signal expressions, we present here 4-piperazinyl-1,8-naphthalimide-functionalized AuNPs for the realization of quantitative recognition of Fe(III) ions with dual (colorimetric and fluorescent) output. The research takes advantage of 1) quantity-controlled chelation-mode transformation of the piperazinyl moiety on the AuNPs towards Fe(III), thereby resulting in an aggregation-dispersion conversion of the AuNPs in solution, and 2) photoinduced electron transfer of a naphthaimide fluorophore on the AuNPs, thus leading to reversible absorption and emission changes.

Engineering a hollow nanocontainer platform with multifunctional molecular machines for tumor-targeted therapy in vitro and in vivo.

In order to selectively target malignant cells and eliminate severe side effects of conventional chemotherapy, biocompatible and redox-responsive hollow nanocontainers with tumor specificity were fabricated. The mechanized nanocontainers were achieved by anchoring mechanically interlocked molecules, i.e.

Chirality control for in situ preparation of gold nanoparticle superstructures directed by a coordinatable organogelator.

Imposing chirality into nanoscale superstructures is a major step forward toward systematic understanding and utilization of nanomaterials. In an attempt to achieve tunable chirality during in situ preparation of hybrid nanomaterials, we here report a novel unimolecular strategy of employing a coordinatable organogelator for the realization of chirality control in the formation of gold nanoparticle superstructures. The work takes advantage of thermally reversible sol-gel transition of the chiral dispersion as template, which causes different micelle properties that can influence the coordination ability between the organogelator and Au(III) ions.

Preparation of stable, water-soluble, highly luminescence quantum dots with small hydrodynamic sizes.

This work presents a simple method to prepare water-soluble alloyed CdSe-ZnS quantum dots, which photoluminescence are tunable from green to red continuously, through replacing the hydrophobic oleic acid stabilizers with hydrophilic thiol molecules. 3-Mercaptopropionic acid and 2-mercaptoethylamine have been used respectively as the surface substitutes to obtain water-soluble quantum dots with negative and positive surface charges. The methods achieved highly efficient phase transfer (approximately 100%) of quantum dots from non-polar media to water.