The peak current and potential position for both redox peaks was calculated in Origin Pro. The data sets for the redox peaks were stored as different files as DPV increases or decreases potential in a linear sweep, therefore the data does not have to be split as in section 4.13. The oxidation data ranged from -0.2 V to 0.4 V for Cyt c free in solution or bound to AuNPs, and from -0.2 V to 1.2 V when the system contained both Cyt c and porphyrins free in solution or bound to AuNPs. For the reduction data, the inverse potentials were applied from 0.4 V to -0.2 V for Cyt c free in solution or bound to AuNPs, and from 1.2 V to -0.2 V for the Cyt c and porphyrins free in solution. Each section of the cyclic voltammogram was then plotted, and the background was subtracted. To background subtract, a 4 th order polynomial fit was selected, and nodes were placed along the cyclic voltammogram at points acting as anchors. The region of interest for Cyt c between -0.1 V and 0.2 V was left clear of nodes, allowing a background to be created in this region. The region of interest for the porphyrins ranged between 0.3 V to 0.6 V for the first redox peak, and 0.7 V to 1 V for the second peak; both regions were left clear of nodes allowing a background to be created in both. The interpolation method was changed from line to Spline and the background was subtracted. The resulting data were plotted as a new graph in Origin Pro and using the quick peaks tool the region of interest mentioned previously was selected. The baseline mode was set to 2 nd derivative with the range of curve within ROI selected, and the smoothing method used for the baseline was adjacent averaging with a maximum of 8 anchor points and the connect method set as the line. The peak finding method was set to a local maximum determined by 15 local points, and peak filtering was turned on to a threshold height of 20%. Once the peaks were identified by the software, their heights and position were output to a table.