Paper-based FRET for the direct detection of collagen triple helix

In order to develop improved diagnosis and therapies for the highly prevalent chronic fibroproliferative diseases, it is of utmost importance to construct efficient assays to detect collagen biomarkers. We have successfully created a paper-based FRET assay for the fast, inexpensive and direct detection of collagen triple helix. We have demonstrated that the adsorption of the dye-labeled probe peptide onto the GO-immobilized paper quenches the fluorescence of the dye, while the hybridization of the probe peptide with the target collagen peptide results in the desorption of the probe peptide from GO, thus restoring the fluorescence. We have also shown that this novel assay is highly specific to the target collagen peptide sequence with little interference from other proteins, and it can be applied for quantitative detection in complex biological fluids. Our integration of the GO-based FRET assay with a patterned paper provides a powerful new tool for the detection of collagen molecules with many superior features: tiny volumes of samples, multichannel detection mode, easy operation and low-cost equipment. This assay may have promising applications to fast screen multiple target collagen sequences for the discovery of new collagen biomarkers.