Photolithographic Fabrication of Upconversion Barcodes for Multiplexed Molecular Detection

Abstract The demands of clinical diagnostics and genetic analysis for high‐performance multiplex detection systems have driven substantial advancement from planar microarrays to suspension arrays for accurate encoding, inventorying, and detecting extensive databases of biomolecules. Despite the multitude of related works and the commercial availability of nanostructured arrays for biodetection, it remains challenging to develop biodetection modules of massive coding permutation with high production rates and fast reaction kinetics . Herein, the concurrent improvement in both production and coding capacities without compromising detection kinetics is reported using lithography‐based upconversion barcodes as the basis for bioassay detection modules. This method exploits microstructural forms of dense graphical encoding, with barcode production up to 10⁹ per run at extensive color permutations. The upconversion barcoding technique requires a million times lower analyte consumption compared to currently available technologies. Moreover, the use of upconversion barcodes is demonstrated in a DNA hybridization test with high target specificity, low detection limit, and ease of flexible surface bioconjugation, enabling potential development of biomarkers in the analysis of massive proteomics, genomics, and metabolomics data.