Localized surface plasmon resonance (LSPR) gives many advantages in biosensor applications such as the short analysis time and the cost-effectiveness. However, previous LSPR sensor are low sensitivity due to a reproducibility issue. In this study, a LSPR chip based on gold nanoparticles (Au NPs) for detection of hepatitis B virus marker (HBsAg) with high reproducibility. The LSPR chips were simply nano-patterned with AuNPs and showed sufficient sensitivity to detect HBsAg at concentrations of 1 pg/mL. In addition, an enhancing receptor was used to obtain lower limit of detection (LOD) The enhancing receptor was prepared with three different sizes of Au NPs modified with secondary antibody to enhance LSPR signal. The LSPR chip showed hundredfolded sensitivity by using enhancing receptor and consequently LOD was 100 fg/mL.