A self-assembled quantum dot probe for detecting beta-lactamase activity.

Chenjie Xu; Bengang Xing; Jianghong Rao

doi:10.1016/j.bbrc.2006.03.225

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A self-assembled quantum dot probe for detecting beta-lactamase activity.

Chenjie Xu·Bengang Xing·Jianghong Rao

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Abstract

This communication describes a quantum dot probe that can be activated by a reporter enzyme, beta-lactamase. Our design is based on the principle of fluorescence resonance energy transfer (FRET). A biotinylated beta-lactamase substrate was labeled with a carbocyanine dye, Cy5, and immobilized on the surface of quantum dots through the binding of biotin to streptavidin pre-coated on the quantum dots. In assembling this nanoprobe, we have found that both the distance between substrates and the quantum dot surface, and the density of substrates are important for its function. The fluorescence emission from quantum dots can be efficiently quenched (up to 95%) by Cy5 due to FRET. Our final quantum dot probe, assembled with QD605 and 1:1 mixture of biotin and a Cy5-labeled lactam, can be activated by 32microg/mL of beta-lactamase with 4-fold increase in the fluorescence emission.

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Fluorescence Resonance Energy Transfer Fluorescent Dyes Molecular Probe Techniques Quantum Dots Staining and Labeling beta-Lactamases Journal Article Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't

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Chenjie Xu, Bengang Xing, Jianghong Rao. 2006-04-19. A self-assembled quantum dot probe for detecting beta-lactamase activity.. https://doi.org/10.1016/j.bbrc.2006.03.225

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