Binding of thiolated nucleotide sequences to the surface of gold nanoparticles was confirmed by determining their zeta potential, Figure . Unfunctionalised gold nanoparticles, Sequence-A and Sequence-B functionalised gold nanoparticles, and aggregated nanoparticles exhibited zeta potentials of -21.9 ± 5.21 mV, -15.37 ± 3.23 mV -20.77 ±2.95 mV and -17.8 ± 0.95 mV, respectively. These results suggest that functionalised nanoparticle surfaces have marginally greater zeta potentials, although not significant (p>0.01), when compared to unfunctionalised nanoparticles. Furthermore, the aggregates, which are formed from a construct of Sequence-A and Sequence-B functionalised gold nanoparticles, as expected exhibit a zeta potential in-between the zeta potential of Sequence-A and Sequence-B functionalised gold nanoparticles.