Analytical Devices Based on Direct Synthesis of DNA on Paper

TLDR

The paper addresses a growing need in clinical diagnostics for parallel, multiplex analysis of biomarkers from small biological samples. The study presents a new procedure for assembling arrays of single‑stranded DNA and proteins on paper. The method synthesizes DNA oligonucleotides covalently attached to paper, then assembles microzones of DNA‑conjugated paper into arrays that can simultaneously capture DNA, DNA‑conjugated protein antigens, and DNA‑conjugated antibodies, enabling detection of fluorophore‑linked DNA and protein antigens via sandwich ELISAs and forming paper‑based devices for DNA and antibody detection. The synthesis yields 32 % full‑length 32‑mer oligonucleotides, and the resulting paper‑anchored ssDNA arrays can be used to build devices that simultaneously detect DNA and antibodies, including simple microfluidic paper‑based formats.

Abstract

This paper addresses a growing need in clinical diagnostics for parallel, multiplex analysis of biomarkers from small biological samples. It describes a new procedure for assembling arrays of ssDNA and proteins on paper. This method starts with the synthesis of DNA oligonucleotides covalently linked to paper and proceeds to assemble microzones of DNA-conjugated paper into arrays capable of simultaneously capturing DNA, DNA-conjugated protein antigens, and DNA-conjugated antibodies. The synthesis of ssDNA oligonucleotides on paper is convenient and effective with 32% of the oligonucleotides cleaved and eluted from the paper substrate being full-length by HPLC for a 32-mer. These ssDNA arrays can be used to detect fluorophore-linked DNA oligonucleotides in solution, and as the basis for DNA-directed assembly of arrays of DNA-conjugated capture antibodies on paper, detect protein antigens by sandwich ELISAs. Paper-anchored ssDNA arrays with different sequences can be used to assemble paper-based devices capable of detecting DNA and antibodies in the same device and enable simple microfluidic paper-based devices.