Plasmonic Nanomaterials-Based Flexible Strip for the SERS Detection of Gouty Arthritis

Flexible biochips that enable sensitive detection and simultaneous quantification of biomarkers are of great importance in the field of point-of-care testing. Cellulose paper-based biochips have been employed for the diagnostics and biosensing owing to their unique advantages such as high specific surface area, flexibility, and abundance. Recently, surface-enhanced Raman scattering (SERS)-based flexible biochips have attracted a great deal of research attention for disease detection due to their rapid, sensitive, and noninvasive sensing abilities. Phenomenal progress in the synthesis of structure-controlled plasmonic nanomaterials has made SERS a powerful sensing platform for disease diagnosis and trace detection. Owing to their outstanding optical properties, noble metal nanomaterials are excellent candidates for chemical and biological sensing applications. Yolk-shell structured plasmonic nanomaterials, which consist of solid nanomaterials as the core and nanocage as the shell, have been demonstrated to exhibit extraordinary optical properties due to their high surface to volume ratio and the high density of the electromagnetic fields compared to their solid counterparts. Here, we demonstrate the flexible plasmonic biochips for the SERS-based detection of uric acid (UA). Flexible strips exhibited excellent sensing performance with a detection limit of around 10 µM of UA, which is lower than the average level of UA in tears. This rapid and sensitive detection method enables the noninvasive diagnosis of gouty arthritis.