Bridging the neighbor plasma coupling on curved surface array for early hepatocellular carcinoma detection

Abstract Detecting biomarkers with high sensitivity is key for the early diagnosis of hepatocellular carcinoma (HCC). Nanostructure units with knobby surface are bridged to obtain significant surface-enhanced Raman scattering (SERS) signals. This changes the plasma coupling mode and the hotspots distribution between neighboring units as confirmed by finite-difference time-domain simulations. These arrays of bridged knobby units are used to quantitatively analyze the concentrations of α-Fetoprotein (AFP) and AFP-L3 by immunoanalysis using a combination of frequency shifts and intensity changes of SERS. By using these arrays of bridged knobby units as SERS immunochips, the detection limits of AFP and AFP-L3 decrease to 3 pg/mL. This immunoanalytic method has potential value for the diagnosis of early liver cancer in patients, offering advantages of convenience, time saving, low detection limit, and high precision.