Gold, colloidal filtration

Figure 2. Electrophoretic profiles of glucan synthase fractions purified from celery. Proteins were transferred to nitrocellulose and stained by colloidal gold. Symbols PM, plasma membranes SOL, CHAPS-solubilized RC, reconstituted glucan synthase preparations. Plasma membranes were isolated by two-phase partitioning. Specific activities of the three membrane preparations were 398, 1355, and 626 nmol/min/mg, respectively. The low specific activity of RC relative to SOL may be a reflection of enzyme instability following the gel filtration step.

Similarly to the codeposition procedure above, the metal can also be delivered as nanoparticles to the colloidal crystal template, but in this case after preparation of the template. This was demonstrated for gold nanoparticles, which were filled into the interstitial sites of a polymer opal by filtering a gold nanoparticle suspension through the preassembled opal with a filter small enough to hold back the nanoparticles [33]. The templating opal was prepared before in very much the same way by filtration of a PS latex suspension. 

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