A simple and universal "turn-on" detection platform for proteases based on surface enhanced Raman scattering (SERS)

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Protease detection is crucial in diagnostics and research.
• Existing methods often lack sensitivity or simplicity.
• Surface-enhanced Raman scattering (SERS) offers a sensitive detection platform.

Purpose of the Study:

• To develop a novel "turn-on" SERS-based strategy for protease detection.
• To establish a facile and highly sensitive SERS biosensor for enzyme activity.
• To demonstrate the adaptability of the method for various proteases.

Main Methods:

• Utilized 4-mercaptobenzoic acid (4-MBA) labeled gold nanoparticles (AuNPs).
• Employed enzyme-mediated non-cross-linking aggregation of AuNPs triggered by protease activity.
• Analyzed changes in SERS signals of 4-MBA due to nanoparticle aggregation and "Hot Spot" formation.

Main Results:

• Achieved a "turn-on" SERS response for protease detection.
• Demonstrated high sensitivity with a limit of detection of 85 fM for trypsin (S/N=3:1).
• Exhibited excellent selectivity for target proteases and applicability in complex samples.

Conclusions:

• The developed SERS strategy provides a sensitive, selective, and simple method for protease detection.
• The biosensor shows potential as a general approach for enzyme activity-based protease detection.
• This method highlights the superiority and versatility of SERS biosensors in biological applications.