A series of novel bimetallic PtCu nanochains have been synthesized through a water-based mild chemical route, and their compositions (Pt(x)Cu(1-x)) can be conveniently tuned at the mesoscopic scale by a facile dealloying process. These nanomaterials have been characterized by transmission electron microscope (TEM), high-resolution TEM (HRTEM), X-ray powder diffraction (XRD), and elemental analysis. They have different compositions (Pt88Cu12, Pt75Cu25, and Pt50Cu50) but have similar morphology. Electrochemical activity of these nanomaterials is compared to Pt and nanochains of Pt when they are chemically modified onto a glassy carbon electrode. Electrochemical measurements demonstrate that the sensors made by these PtCu nanomaterials are very sensitive and selective for glucose detection due to the wiring of dispersed crystals, porous nanostructure, clean surface, and synergetic electronic effects of the alloyed atoms. Among them, the modified electrode made of Pt75Cu25 shows the best performance. The superior catalytic activity and selectivity make nanomaterials, via the green synthesis, very promising for applications in direct biosensing of glucose.