Though known about and used for centuries, gold nanoparticles and their resulting chemistry remain an active area of research to this day. In particular, much effort has been directed at synthesising gold nanoparticles of controlled sizes and morphologies. Gold particles around 2-100 nm in diameter contain localised surface Plasmon resonances (LSPR), which give them distinct spectral properties that can be harnessed for colorimetric sensor development. For example, gold nanostars-a type of highly branched gold nanoparticle-have two LSPR: one due to oscillations in the star body and the other due to oscillations in the star spikes. In contrast, gold nanoparticles smaller than 2 nm, also known as nanoclusters, are fluorescent and this feature can be exploited for biosensor design. In this thesis, we present evidence that nanostars can reshape into more rounded nanoparticles through interactions with bovine serum albumin (BSA). Additionally, as byproducts of this reshaping process, fluorescent gold nanoclusters are formed. Though unmodified nanostars do not fluoresce, we have been able to create BSA stabilised nanoclusters that fluoresce green (545 nm) when excited at 450 nm and red (660 nm) when excited at 640 nm. This is believed to be the first time such nanocluster have been generated from nanostars. This combination of red fluorescence, green fluorescence, and changing colourimetric properties resulting from nanostar reshaping and concomitant nanocluster formation suggest that the process is highly versatile to the creation of biosensors.