Au-Pt-Ni nanochains as dopamine catalysts: role of elements and their spatial distribution

Multi-element materials can improve biosensing ability as each element can catalyze different steps in a reaction pathway. By combining Pt and Ni on self-assembled 1D gold nanochains and controlling their spatial distribution, a detailed understanding of each element's role in dopamine oxidation is developed. In addition, the developed synthesis process provides a simple way to fabricate multi-element composites for electrocatalytic applications based on electrical double-layer formation on the surface of charged nanoparticles. The performance parameters of the catalyst, such as its sensitivity, limit of detection, and range of operation for dopamine sensing, are optimized by changing the relative ratios of Pt : Ni and the morphology of the Pt and Ni domains, using the developed understanding. The morphology of the domains also affects the oxidation state of Ni, which is crucial to the performance of the electrocatalyst.