Quantum dots and their potential biomedical applications

Quantum dots (QDs) are semiconductor-based nanocrystals. These nanoparticles have exhibited their unique optical and electronic properties. With these characteristics, QDs attracted scientists interest in biomedical areas such as bioimaging, drug delivery and biosensors apart from other applications like photocatalysis, light-emitting, and solar cells in recent years, and plenty of QDs and QD-based materials have exhibited their unique properties in their applications of biomedical areas. Nevertheless, the potential toxicity of QDs becomes the limitation of QDs application in biomedical areas. The toxicity of QDs might come from: the toxicity core material of QDs; the toxicity substances from the surface of QDs; the free radicals or reactive species released from QDs; the biological environment induced QDs toxicity. In this article, we review the properties of QDs, the applications of QDs in different biomedical fields, how QDs cause toxicity, and how to reduce or prevent QDs potential toxicity. In the future, we expect the improvement and further application of QDs in biomedical areas.