Penicillamine-Capped Red-Emitting Gold Nanoclusters for Therapeutic Application

Abstract

Subnanometer-sized metal nanoclusters (NCs) with diameters <2 nm have emerged as promising materials in biomedical applications. Here, we report the synthesis of near-infrared (NIR)-emitting Au 14 nanoclusters using a small therapeutic molecule, D-penicillamine (DPA), as a surface stabilizing agent. We have characterized the morphology and composition of as-synthesized NCs using electron microscopy and mass spectrometry techniques. The photophysics of the NCs was investigated by UV−vis and photoluminescence (PL) spectroscopy. We found molecule-like features with three distinctive absorption bands at 390, 456, and 590 nm and a photoemission band at 696 nm. We observed that Au NCs specifically inhibited cancer cells dose-dependently through preferential uptake and imparted significant intracellular ROS. They did not show any acute toxicity in C57BL/6 mice at a dosage of 10 mg/kg, with predominant accumulation in the kidneys at the end of 24 h.

Experimental and computational insights into luminescence in atomically precise bimetallic Au6−nCun(MPA)5 (n = 0–2) clusters

“…3,[7][8][9] Metal NCs exhibit fascinating properties like a distinctive HOMO-LUMO gap, tunable photoluminescence properties, and biocompatibility, which endow them with broad applications in optoelectronics, drug delivery, sensing, and bioimaging. 3,[10][11][12] Noble metal NCs display size-dependent optical properties and tunable PL over the visible and nearinfrared regions of the spectrum by controlling the number of atoms or by changing the ligand nature. 6,[13][14][15] The synthesis of metal NCs involves two well-known strategies: top-down and bottom-up approaches.…”

Enhanced Luminescence in Zn+2-Induced Au14 Nanocluster Aggregates

“…We examined the excitation-dependent PL of Au NCs and Au nanoaggregates in the range of 340–580 nm (Figure S9). The excitation wavelength-dependent PL emission of both Au NCs and Au nanoaggregates suggests that emission originates from a homogeneous excited state . We recorded the absorption and PL spectra after 1 week to check the optical stability of Au nanoaggregates.…”

“…D-Penicillaminecapped Au NCs were prepared using our previously reported procedure. 15 Typically, in 10 mL of HPLC water, 400 μL of HAuCl 4 •3H 2 O (100 mM) was added and then ligand DPA (800 μL, 100 mM) was added to the reaction mixture. Immediately, the solution color changes from light yellow to colorless and it indicates the formation of the Au(I)-DPA complex.…”

Atomically Precise Ni Nanoclusters for Improving Hydrogen Evolution Reaction Performance

“…Atomically precise metal nanoclusters (NCs) have been widely studied for a variety of applications such as catalysis, sensing, photovoltaics, optics, etc. − Numerous efforts have been devoted toward the development and understanding of noble metals NCs of Au and Ag both experimentally as well as theoretically for electrocatalytic application. ,, For example, Au 25 /MoS 2 and Ag NCs/MoS 2 composites have demonstrated superior HER performance due to efficient charge separation at the interface. Earth-abundant and cost-effective Ni metal is a promising candidate for HER, but less effort has been given to developing Ni clusters for electrocatalytic applications. , In this respect, developing a green synthesis strategy to stabilize Ni NCs in aqueous media will be advantageous.…”