A method of fracturing multiple productive zones of a subterranean formation penetrated by a wellbore is disclosed. The method comprises injecting a fracturing fluid into each of the multiple production zones at a pressure sufficient to enlarge or create fractures in the multiple productive zones, wherein the fracturing fluid comprises an upconverting nanoparticle that has a host material, a dopant, and a surface modification such that the upconverting nanoparticle is soluble or dispersible in water, a hydrocarbon oil, or a combination thereof; recovering a fluid from one or more of the multiple production zones; detecting the upconverting nanoparticle in the recovered fluid by exposing the recovered fluid to an excitation radiation having a monochromatic wavelength; and identifying the zone that produces the recovered fluid or monitoring an amount of water or oil in the produced fluid by measuring an optical property of the upconverting nanoparticle in the recovered fluid.