LAUSR

This work reports a portable, origami-type paper device with a plasmonic fluor-labeled microneedle sensing module for the multiplexed quantification of anemia biomarkers in whole blood. Sequential steps, including serum separation, target enrichment, and multiplexed readout by a gel imager, are rapidly accomplished with the flexible and highly integrated device. The microneedle array enabled efficient sampling of trace targets from ng mL-1 to pg mL-1 level. Combined with the plasmonic fluor label, the signal is improved by ≈7.6 folds compared with the flat substrate-based assay. The device is applied to simultaneously quantify hemoglobin (Hb), ferritin, folic acid (FA), and vitamin B12 (VB12 ), which are four anemia biomarkers distributed in different environments with different concentration ranges. Featured by the small sample volume (150 µL), short assay time (20 min), low cost (2 $), robust stability, and user-friendliness, the device is promising for the rapid and accurate diagnosis of anemia in real practice.