Rapid, Quantitative, and Ultrasensitive Point-of-Care Testing: A Portable SERS Reader for Lateral Flow Assays in Clinical Chemistry.

The design of a portable Raman/SERS-LFA reader with line illumination using a custom-made fiber optic probe for rapid, quantitative, and ultrasensitive point-of-care testing (POCT) is presented. The pregnancy hormone human chorionic gonadotropin (hCG) is detectable in clinical samples within only 2-5 s down to approximately 1.6 mIU mL-1 . This acquisition time is several orders of magnitude shorter than those of existing approaches requiring expensive Raman instrumentation, and the method is 15-times more sensitive than a commercially available lateral flow assay (LFA) as the gold standard. The SERS-LFA technology paves the way for affordable, quantitative, and ultrasensitive POCT with multiplexing potential in real-world applications, ranging from clinical chemistry to food and environmental analysis as well as drug and biowarfare agent testing.