LAUSR

This study proposes a magnetic biochip that uses surface-enhanced Raman scattering (SERS) for antigen detection. The biochip was a sandwich structure containing alternating layers of gold and magnetic Fe2O3 nanoparticles. Both single (Au/Fe2O3/Au) and multilayer (Au/Fe2O3/Au/Fe2O3/Au) chips containing Fe2O3 nanoparticles were fabricated to detect bovine serum albumin (BSA). The single-layer chip detected the BSA antigen at a signal-to-noise ratio (SNR) of 5.0. Peaks detected between 1000 and 1500 cm−1 corresponded to various carbon chains. With more Fe2O3 layers, bond resonance was enhanced via the Hall effect. The distribution of electromagnetic field enhancement was determined via SERS. The signal from the single-layer chip containing Au nanoparticles was measured in an external magnetic field. Maximum signal strength was recorded in a field strength of 12.5 gauss. We observed peaks due to other carbon–hydrogen molecules in a 62.5-gauss field. The magnetic field could improve the resolution and selectivity of sample observations.