Abstract
Molecular biomarkers play a key role in the clinic, aiding in diagnostics and prognostics, and in the research laboratory, contributing to our basic understanding of diseases. Detecting multiple and diverse molecular biomarkers within a single accessible assay would have great utility, providing a more comprehensive picture for clinical evaluation and research, but is a challenge with standard methods. Here, we report programmable DNA nanoswitches for multiplexed detection of up to 6 biomarkers at once with each combination of biomarkers producing a unique barcode signature among 64 possibilities. As a defining feature of our method, we show "mixed multiplexing" for simultaneous barcoded detection of different types of biomolecules, for example, DNA, RNA, antibody, and protein in a single assay. To demonstrate clinical potential, we show multiplexed detection of a prostate cancer biomarker panel in serum that includes two microRNA sequences and prostate specific antigen.