Platinum-based catalysts are regarded as premier anodic electrocatalysts in direct methanol fuel cells due to their great catalytic activities but hampered by its non-benign conventional synthesis, and high production expenses. This study exploited a new sustainable pathway of a biosynthesis route using the biomass plant extract of sugarcane bagasse in a facile single-step process guided by the principle of green chemistry performing enhanced functionalized bio-platinum nanoparticles. The physiochemical characterization, along with the bio-reductive mechanism were comprehensively discussed. The electrochemical activity was performed by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy measurements. The novel nano-spheroid biosynthesized Pt NPs manifested a high ECSA of approximately 95 m(2)/g with an enhanced current density of 400 mA/mg(catalyst)(-1), which were 3 to 4 times higher than those of Pt black commercial. The discovery of bioactive compounds from the dominant group of polyphenolics, flavonoids, carboxylic acids, and proteins suggested that they were accountable for the bio-reductive mechanism.