Quantum Dot Nanobarcodes: Epitaxial Assembly of Nanoparticle−Polymer Complexes in Homogeneous Solution

Abstract

Multiplexed nanobarcodes have been prepared with quantum dots (QDs) and alternating amphiphilic copolymers consisting of hydrocarbons and maleic anhydride groups. In homogeneous solution, the QD−polymer complexes grow epitaxially into nanobeads of narrow size dispersity, which has been previously achieved only for micrometer-sized beads in the presence of solid supports. As a result of this new nanostructure formation mechanism, more than 250 QDs can be loaded into a nanobead of 100 nm in diameter. A model assay for sensitive detection of human prostate specific antigen has also been demonstrated using the QD-nanobeads as fluorescent reporters. This nanoparticle−polymer self-assembly technology is capable of producing a variety of nanostructures and is expected to open new opportunities in nanoparticle-based ultrasensitive detection and imaging.