Abstract
Lanthanide-doped nanocrystals have shown great promise in bio-detection due to their outstanding luminescent properties, including large Stokes shift and sharp emission bands. Herein, we describe an in vitro detection of STAT3 by using an all-nanocrystal biosensing system that takes advantage of inter-particle energy transfer between two types of lanthanide-doped nanocrystals. We investigate the effect of nanocrystal size on the sensing performance and find that smaller nanocrystals offer a lower detection limit and larger dynamic range. As STAT3 is identified as an oncogene aberrantly activated and expressed in malignant transformation and tumorigenesis, our study thus holds promise for cancer diagnosis and therapy.