The present disclosure relates to a complex for detecting a target material comprising upconverting nanoparticles； and at least one target material specific aptamer-quencher, connected through a linker with the upconverting nanoparticles, a method of preparing the same, a kit for detecting a target material comprising the same, and a method of detecting a target material using the same.According to the present disclosure, different target materials in samples can be quantified or detected accurately based on luminescence resonance energy transfer (LRET) of the upconverting nanoparticles (UCNPs) excited by a near infrared (NIR) light source.
