KCS

Rapid, user-friendly and versatile lateral flow (LF) strips have been extensively used for point-of-care (POC) and site-of-care (SOC) diagnostics. However, they have major limitations in terms of detection sensitivity and limited quantification capability. To resolve these problems, we recently developed a novel surface-enhanced Raman scattering (SERS)-based LF assay sensor for the quantitative analysis of a specific biomarker [1,2]. To assess the potential utility of SERS-based LF sensor in rheumatoid arthritis (RA) diagnosis, we extended the use of SERS-based LF assay platform to clinical samples of RA patients. In the first part of this work, the SERS-based LF assay for autoantibody against citrullinated peptide (anti-CCP) spiked in human serum was performed. For this purpose, CCP-immobilized LF strips and human IgG-conjugated SERS nano tags were prepared. Then the SERS signal of immunocomplexes on the test line was measured. Second, the SERS-based LF assay sensor was applied for real RA patient human sera collected by Hanyang University Hospital for Rheumatic Diseases. The clinical samples were divided into anti-CCP positive and anti-CCP negative groups according to their assay results by a commercially available ELISA kit. Next, the SERS-based LF assay results were compared to those measured by the commercially available ELISA kit. Statistical analyses were performed to evaluate the correlation between the ELISA and SERS-based LF assay results for both anti-CCP positive and negative patient groups.