Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Analytical Chemistry

Microbeads boast dual functions

July 31, 2006 | A version of this story appeared in Volume 84, Issue 31

Micrometer-sized beads arebecoming a popular format for performing biological assays. These beads must be both manipulatable and detectable. Shuming Nie and coworkers at Emory University and Georgia Institute of Technology report that they can embed quantum dots and iron oxide nanocrystals in the pores of mesoporous silica beads to create dual-function microcarriers that can be simultaneously encoded, enriched, and separated (Anal. Chem., DOI: 10.1021/ac0610309). The beads are doped by mixing the silica beads with solutions of quantum dots and iron oxide nanocrystals, either simultaneously or sequentially. The iron oxide nanocrystals reduce the fluorescence from the quantum dots, but this attenuation can be lessened by choosing longer excitation wavelengths and by incorporating only about 100,000 iron oxide nanocrystals per bead. Nie and coworkers show that they can separate magnetic beads encoded with red quantum dots from nonmagnetic beads encoded with green quantum dots. The method is "elegant, simple, and effective," comments Shawn P. Mulvaney of the Naval Research Laboratory. "They can potentially tune both the magnetic and optical properties."

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.