Facile preparation of water-soluble fluorescent gold nanoclusters

A simple one-pot strategy of preparing small fluorescent AuNCs using a mild reductant, tetrakis-
(hydroxymethyl)phosphonium chloride (THPC). For biological imaging applications, a zwitterionic functional ligand, D-penicillamine (DPA), was chosen as a capping agent to endow the gold clusters with good stability in aqueous solvent.

Materiales


1. Tetrakis(hydroxymethyl) phosphonium chloride (THPC, P(CH2OH)4Cl, 80% aqueous solution),
2. D-penicillamine (DPA),
3. Rhodamine 6G
4. Gold(III) chloride trihydrate (HAuCl4.3H2O)
5. Sodium borohydride (NaBH4)
6. High purity deionized water

Síntesis


12 ml THPC (80%) was added to 47 ml NaOH solution (6 mM) at 37 C. The mixture was stirred for 3
min, followed by rapid addition of a solution of HAuCl4 (0.67ml, 2% by mass) and DPA (2.5 ml, 0.1 M). The reaction, during which the colorless solution slowly turned light yellow, was stopped after stirring for 15 h.


As-prepared AuNCs were purified by triple centrifugation filtration, using Nanosep filters (PallNanosep, Ann Arbor, MI) with a molecular weight cut-off of 3 kDa to remove impurities. The yellowish DPA–AuNCs
remaining on the filter could be re-suspended readily in water,and the solution was stored at 4 C for later use

Tomado de:


Facile preparation of water-soluble fluorescent gold nanoclusters for cellular imaging applications

Li Shang,a Ren e M. D€orlich,a Stefan Brandholt,a Reinhard Schneider,b Vanessa Trouillet,c Michael Bruns,c
Dagmar Gerthsenb and G. Ulrich Nienhaus

Nanoscale, 2011, 3, 2009

http://dx.doi.org/10.1039/c0nr00947d