Oriented Antibody Functionalized Plasmonic Yolk-Shell-Satellite Nanostructures for Ultrasensitive SERS-Based Lateral...

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Conventional gold nanoparticle (AuNP)-based lateral flow immunoassays (LFIAs) for matrix metalloproteinase-9 (MMP-9) detection exhibit limited sensitivity.
• MMP-9 is a critical biomarker for diseases such as dry eye disease and various cancers.

Purpose of the Study:

• To develop an ultrasensitive surface-enhanced Raman scattering (SERS)-based LFIA for enhanced MMP-9 detection.
• To improve upon the sensitivity limitations of traditional AuNP-LFIA methods.

Main Methods:

• Fabrication of plasmonic yolk-shell-satellite nanostructures (YSSNs) as SERS tags.
• Functionalization of YSSNs with bifunctional 4-mercaptophenylboronic acid (MPBA) to enhance antibody orientation and act as Raman reporters.
• Development of a SERS-LFIA platform for MMP-9 quantification.

Main Results:

• The SERS-LFIA achieved a significantly lower limit of detection (LOD) of 0.0056 ng·mL^-1 in PBS, representing a 305-fold improvement over conventional AuNP-LFIA.
• The assay demonstrated reliable linear detection in biological matrices, with LODs of 0.051 ng·mL^-1 in serum and 0.030 ng·mL^-1 in tears.
• YSSNs provided strong SERS enhancement, and MPBA improved antibody orientation and Raman signal.

Conclusions:

• The developed SERS-LFIA platform offers a highly sensitive and reliable method for MMP-9 detection.
• This advanced assay holds significant potential for early and accurate disease diagnostics, particularly for dry eye disease and cancer.