Gold Nanostar@Prussian Blue Core-Shell Nanoparticles for the Detection of Acute Myocardial Infarction Biomarkers

¹ State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 211189, China
² Southeast University-Monash University Joint Graduate School, Suzhou, 215123, China

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Plasmonic nanomaterials have significantly advanced the detection of trace biomarkers, with Prussian blue (PB) emerging as a prominent candidate in biosensing applications. Traditional Raman reporters often exhibit multiple spectral bands in the fingerprint region, leading to inevitable overlap with endogenous biomolecules. In contrast, PB acts as a highly sensitive, background-free resonance Raman reporter. It presents a single, strong, and sharp band in the cellular Raman silent region, completely resolving its Raman signal from biological species without the need for complex spectral unmixing. In this study, we developed a novel surface-enhanced resonance Raman scattering (SERS) probe with a high signal-to-background ratio (SBR) by assembling PB onto plasmonic gold nanostar (AuNS) cores. Advancing beyond prior PB-based probes, this core-shell design uniquely leverages the tunable anisotropic plasmonic field of the multi-spiked AuNS core to significantly amplify the Raman signal of the PB shell. To maximize the enhancement of the PB SERS signal, we systematically compared AuNS cores with various spike morphologies and identified the optimal core-shell architecture based on maximum SERS intensity and signal reproducibility. The selected AuNS@PB nanoparticles were successfully applied to detect the acute myocardial infarction (AMI) biomarker, Creatine Kinase MB (CK-MB), at extremely low concentrations, fundamentally improving detection sensitivity and accuracy. The optimized SERRS probe achieved an ultra-low limit of detection (LOD) of 10 fg/mL, demonstrating its exceptional potential as a robust platform for the early clinical diagnosis of AMI.