Gold nanoparticles from commercially available colloids were deposited onto a hydrogen-terminated silicon
substrate without the use of a polyelectrolyte linker by the addition of HF acid. The deposition density
was shown to be controlled over three orders of magnitude by varying the colloid concentration, and
finer control is achieved by varying the deposition time. In order to minimise agglomeration, however, we
show that deposition times should be minimised since nanoparticle agglomeration increases rapidly over
the first 2 min after the addition of HF. To increase nanoparticle density without increasing agglomeration,
we show that successive depositions of short times linearly increase the deposition density without
increasing the agglomeration of nanoparticles