Multiplexed Detection of Anthrax Sequences with Quantum Dot Nanoprobes

We demonstrate a bio-agent detection scheme using colocalization of target-selective quantum dot nanoprobes. The presence of a target is shown through the colocalized emissions of bound events and easily distinguished with colorimetric measurements, negating an additional step for separation of unbound probes. Multiplexed detection can be achieved by multiple quantum dots with spectrally separable emissions. Genetic analysis of anthrax pathogenicity-relevant sequences serves as a multiplexed example of this approach. Furthermore, this method shares characteristics with a homogeneous format which leads to better reaction kinetics and faster detection compared with conventional solid-phase approaches.