Single functional magnetic-bead as universal biosensing platform for trace analyte detection using SERS-nanobioprobe.

Area of Science:

• Nanotechnology
• Biosensing
• Analytical Chemistry

Background:

• Surface-Enhanced Raman Scattering (SERS) biosensors offer high sensitivity for bio/chemical analysis.
• Developing universal SERS platforms for reproducible, quantitative detection of trace analytes is challenging.
• Designing SERS nanotags with abundant Raman reporters and suitable structures for biomolecule conjugation is crucial.

Purpose of the Study:

• To introduce a facile single magnetic-bead biosensing platform.
• To develop SERS nanobioprobes with a robust sandwich structure for enhanced detection.
• To demonstrate the platform's capability for ultrasensitive detection of multiple analytes.

Main Methods:

• Fabrication of Au@Raman-Reporters@Ag sandwich-based nanorod tags.
• Conjugation of magnetic beads with antibodies/antigens.
• Integration of magnetic beads and nanorod tags to form a single-bead biosensing platform.
• Utilizing the 3-D structure of magnetic beads for biomolecule capture and enrichment.

Main Results:

• The sandwich-structure nanotags provide high density of Raman reporters and enhanced electromagnetic fields.
• The platform allows for flexible bioconjugation of detection biomolecules.
• Ultrasensitive detection of two small molecules and one protein was successfully achieved in samples.
• The 3-D magnetic bead platform facilitated rapid capture and enrichment of target biomolecules.

Conclusions:

• The developed single magnetic-bead SERS platform offers a universal and reproducible approach for quantitative biosensing.
• The robust sandwich nanotags enhance detection sensitivity through high Raman reporter density and electromagnetic field enhancement.
• This platform demonstrates significant potential for the ultrasensitive detection of various trace bio/chemical targets.