Reverse-Micelle Synthesis of Electrochemically Encoded Quantum Dot Barcodes: Application to Electronic Coding of a Cancer Marker

摘要

Reproducible electrochemically encoded quantum dotn(QD) barcodes were prepared using the reverse-micellensynthetic approach. The encoding elements, Zn2+, Cd2+,nand Pb2+, were confined within a single QD, whichneliminates the cumbersome encapsulation processnused by other common nanoparticle-based barcodenpreparation schemes. The distinct voltammetric strippingnpatterns of Zn2+, Cd2+ and Pb2+ at distinguishablenpotentials with controllable current intensities offernexcellent encoding capability for the prepared electrochemicaln(EC) QDs. Additionally, the simultaneousnmodification of the QD barcode surface with organicnligands during the preparation process make themnpotentially useful in biomedical research. For proof ofnconcept of their application in bioassays, the EC QDnbarcodes were further employed as tags for an immunoassaynof a cancer marker, carcinoembryonic antigenn(CEA). The voltammetric stripping response of thendissolved bardcode tags was proportional to log[CEA]nin the range from 0.01 to 80 ng mL-1, with a detectionnlimit of 3.3 pg mL-1. The synthesized EC QD barcodesnhold considerable potential in biodetection, encryptedninformation, and product tracking.