Polymers mediate a one-pot route for functionalized quantum dot barcodes with a large encoding capacity

With the increasing demands for high-throughput multiplexed bioassays, quantum dot (QD)-encoded microbeads as biocarriers for various bioreactions have attracted considerable attention. However, three key requirements for these biocarriers are still longstanding issues: a stable fluorescence intensity, a large encoding capacity and abundant surface functional groups. Here, a novel one-pot strategy is developed, generating functionalized QD-encoded microspheres with a strong fluorescence intensity and optical stability. With poly(styrene-co-maleic anhydride) (PSMA) molecules as mediators, the encapsulation of QDs and carboxylation of the bead surface are integrated together, greatly improving the preparation efficiency and guaranteeing their potential application in biodetection. Moreover, the mechanism for preparing QD-doped beads is further proposed, which helps to precisely manipulate the preparation process and accurately encode the beads. Through this approach, a single- and dual-color barcode library of QD-encoded microspheres has been successfully established, which demonstrates their great potential in suspension arrays.