Embodiments of a coated substrate comprise a substrate (100) and a multi-layer multi-functional nanoparticle coating (105) having a thickness of up to about 500 nm thereon. The nanoparticle coating (105) comprises an ionic polyelectrolyte layer (110), and an ionic multi-colloid layer disposed over the polyelectrolyte layer (110). The multi-colloid layer comprises hydrophilic colloid ions (130) disposed over and coupled to the polyelectrolyte layer (110), conductive colloid ions (120) disposed over and coupled to the polyelectrolyte layer (110). The conductive colloid ions (120) are separated from the hydrophilic colloid ions (130) by repulsive forces therebetween.