Apart from superior electrocatalytic activity for ORR, nitrogen containing carbon materials are also well-known for their ability to anchoring Pt nanoparticles. It was hypothesized that polydopamine (PDA), an intrinsically N-containing nature inspired polymer, may be able to stabilize platinum nanoclusters due to the binding ability between its amino and catechol groups with Pt precursor. In addition, the inherent fluorescence property of PDA makes it a suitable candidate to study catalyst layer micro-structure and pore size distribution by employing fluorescence microscopy. In this study, PDA was used as a precursor to synthesize ordered carbon nanospheres (100~150 nm) as a catalyst support for polymer electrolyte membrane fuel cells (PEFCs). Morphology of the catalyst was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence microscopy. TEM micrograph (Figure 1) indicated that well-dispersed and uniformly distributed Pt nanoparticles (2-3 nm) was deposited on the PDA based carbon nanospheres (cPDA) as theorized. Electrochemical activity including reaction kinetics of the catalyst was tested in both aqueous and polymer electrolyte (fuel cell condition) media. The performance of the catalyst in a fuel cell was studied at different operating conditions (temperature, relative humidity) and compared with that of the conventional vulcan carbon-based catalyst. Pt durability was assessed in both liquid electrolyte (0.5M H₂SO₄) and FC condition by conducting US department of energy (DOE) recommended accelerated stress test (AST) protocols. The presentation will share the details of catalyst synthesis and characterization as well as the results of its performance in a fuel cell.