Semiconductor Quantum Dots for Biosensing and In Vivo Imaging

Semiconductor quantum dots (QDs) have captivated researchers in the biomedical field over the last decade. Compared to organic dyes and fluorescent proteins, QDs have unique optical properties such as tunable emission spectra, improved brightness, superior photostability, and simultaneous excitation of multiple fluorescence colors. Since the first successful reports on the biological use of QDs a decade ago, QDs and their bioconjugates have been successfully applied to various imaging applications including fixed cell labeling, live-cell imaging,
in

situ
tissue profiling, fluorescence detection and sensing, and
in

vivo
animal imaging. In this review, we will briefly survey the optical properties of QDs, the biofunctionalization strategies, and focus on their biosensing and
in

vivo
imaging applications. We conclude with a discussion on the issues and perspectives on QDs as biosensing probes and
in

vivo
imaging agents.