Modulatory Functionalization of Gold Nanorods Using Supramolecular Assemblies

Abstract

Supramolecular-assembly-mediated functionalization of gold nanorods (GNRs) has been developed by reversible phase transfer between water and oils, which offers a facile method for fabricating robust GNRs with surface-charge tunability. In this regard, trimethylammonium (TMA) GNRs were initially prepared from conventional cetyltrimethylammonium bromide (CTAB) GNRs by means of a ligand-exchange reaction in the presence of an excess amount of TMA ligands. To further expand their functionality and potential applications, electrostatic assemblies of positively charged TMA-GNRs with negatively charged oleate ions were prepared. These assemblies (OA-GNRs) can undergo facile phase transfer from water to hexane. Interestingly, the reversible electrostatic assembly between the TMA and OA ions fabricated onto GNRs can be easily disrupted by treatment with HCl, which removes the OA ions from the GNRs to re-form the TMA-GNRs, which can be made soluble in aqueous media again. In addition, OA-GNRs can be further used for the synthesis of negatively charged GNRs such as 11-mercaptoundecanoic acid (MUA) GNRs, which are hard to prepare directly from CTAB-GNRs. This versatile method for phase transfer and functionalization on GNRs is expected to broaden the scope of their applications in sensing, biomedical imaging, photothermal therapies, and drug delivery systems.

Stimuli-Responsive Nanofibers Containing Gold Nanorods for On-Demand Drug Delivery Platforms

“…The GNRs used in this study were prepared according to the well-known seed-mediated growth method using CTAB, and the stability of GNRs in organic solvents was ensured through surface modification of the GNRs with HS-C 11 -trimethyl ammonium (TMA), as reported by Jeong et al [ 74 ].…”

Smart Delivery Platform Using Core–Shell Nanofibers for Sequential Drug Release in Wound Healing

“…The GNRs used in this study were prepared and characterized as detailed in our previous report. 62,68 Fabrication of CSNFs. To prepare 5 mL of polymeric solution for the core, 0.5 g (10%) PNIPAM, 0.15 g (3%) OpePOSS, and 0.01 g (0.2%) EMI were dissolved in 4 mL of DMF−THF (1:1) and stirred for 4 h at room temperature.…”

On-Demand Drug-Delivery Platform Using Electrospun Nanofibers by Externally Triggered Glass Transition Switch

“…GNRs exhibit significant NIR (650–900 nm) absorption, which is safe for the human body . They also benefit from efficient large-scale synthesis, facile chemical modification, and colloidal stability . The drug loaded into the nanocarriers can be released at a specified location owing to the stimuli-responsive behavior of the nanocarriers through heat generation in the presence of GNRs after NIR irradiation .…”

“…35 They also benefit from efficient large-scale synthesis, facile chemical modification, and colloidal stability. 36 The drug loaded into the nanocarriers can be released at a specified location owing to the stimuli-responsive behavior of the nanocarriers through heat generation in the presence of GNRs after NIR irradiation. 37 GNRs have become a novel category of biomaterials that can respond to stimulation after being embedded in NFs.…”