Silicon Nanowire Field-Effect Transistor as Biosensing Platforms for Post-Translational Modification

Area of Science:

• Biochemistry and Molecular Biology
• Biosensor Technology
• Post-Translational Modifications

Background:

• Protein tyrosine sulfation (PTS) is a critical post-translational modification influencing protein interactions and biological functions.
• Existing methods for monitoring PTS are limited by the instability of sulfated proteins and lack of sensitive detection techniques.

Purpose of the Study:

• To develop a direct, in situ method for monitoring protein tyrosine sulfation (PTS) formation.
• To create a sensitive biosensor for detecting the protein sulfate ester.
• To establish a foundation for next-generation biochips in biomedical research.

Main Methods:

• An in situ PTS system was integrated with a high-sensitivity polysilicon nanowire field-effect transistor (pSNWFET)-based sensor.
• A peptide from P-selectin glycoprotein ligand (PSGL)-1, containing a tyrosine sulfation site, was immobilized on the pSNWFET surface using linker molecules.
• An enzyme-catalyzed sulfation system (tyrosylprotein sulfotransferase and phenol sulfotransferase) was employed to perform PTS on the immobilized peptide.

Main Results:

• The pSNWFET sensor successfully detected enzyme-catalyzed sulfation of the immobilized PSGL-1 peptide in real-time.
• PTS formation was evidenced by a measurable shift in the drain current-gate voltage curves of the pSNWFET.
• The developed system demonstrated the feasibility of directly monitoring PTS.

Conclusions:

• The combined in situ PTS system and pSNWFET sensor provide a novel and sensitive approach for monitoring protein sulfation.
• This method overcomes limitations of existing techniques for detecting unstable sulfated proteins.
• The developed biosensor technology holds significant potential for advancing biomedical research and industrial applications.