Label-Free SERS Detection of Bovine Serum Albumin Protein Based on Au@Ag Core/Shell Nanobricks

摘要

In this study, a simple yet effective protein detection method was established by using bimetallic Au@Ag core-shell nanobrick as SERS active building blocks. The Au@Ag core-shell nanobrick is synthesized by well-defined 'two-step' growing method, enabling uniform and controllable silver shell growth on the surface of the gold nanorods induced by surfactant replacement. The thickness of the silver shell can be programmably adjusted by controlling the amount of silver nitrate in the system, which in turn realized the controllable adjustment of the optical properties of Au@Ag core-shell nanobrick. We selected bovine serum albumin as a model protein and established a highly-sensitive assay for label-free SERS detection of protein. The detection limit can reach to as low as 0.5 μg/mL, enabling promising avenue for its clinical application in ultrasensitive biomarker detection.