Bimetallic platinum nanoparticles provide great potential in development of catalysts for analytical chemistry and many practical applications. These novel materials offer new properties that are distinct from the pure platinum, and lead to more efficiency in various fuel cell and biosensing systems. In particular, the bimetallic approach has shown electrochemical improvement of platinum catalysts which in turn are limited by poisoning and slow sluggish anodic reaction from both systems. Furthermore, the trends of bimetallic design from theoretical studies and recent experimental results are also discussed for incorporation of the second metals such as Ru, Au, Ni, and Pd. The modified electronic and geometric structures of these metal-pairs with remarkable performances have been comprehensively studied. Therefore, the development of new alloy structures and the systematic study of their properties will have a profound impact for advanced energy and biomedical applications.