Highly Sensitive and Reproducible SERS Sensor for Biological pH Detection Based on a Uniform Gold Nanorod Array...

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Sensing

Background:

• Conventional surface-enhanced Raman scattering (SERS)-based pH sensors face repeatability issues due to nanoparticle aggregation variability.
• Developing stable and reproducible SERS platforms is crucial for reliable sensing applications.

Purpose of the Study:

• To fabricate a gold nanorod array platform for enhanced SERS sensitivity and reproducibility.
• To develop a novel bovine serum albumin (BSA)-coated 4-mercaptopyridine (4-MPy)-linked (BMP) SERS-based pH sensor.
• To evaluate the sensor's performance for pH detection in biological samples, specifically mouse blood.

Main Methods:

• Fabrication of a gold nanorod array platform using evaporative self-assembly.
• Development of a BMP SERS probe by coating gold nanorods with BSA and 4-MPy.
• Utilizing the intensity ratio variation of specific peaks in 4-MPy to correlate with pH changes.
• Testing the sensor's accuracy and reliability by measuring pH in C57BL/6 mouse blood.

Main Results:

• The gold nanorod array platform achieved high SERS sensitivity (enhancement factor of 5.6 × 10⁷) with excellent reproducibility (RSD < 8%).
• The BMP SERS-based pH sensor demonstrated high sensitivity for pH detection in the range of 3.0 to 8.0.
• The sensor accurately measured pH in mouse blood, showing good stability and reliability.

Conclusions:

• The developed gold nanorod array platform overcomes the limitations of nanoparticle aggregation in conventional SERS sensors.
• The BMP SERS-based pH sensor offers a stable, reliable, and accurate method for pH monitoring.
• This technology holds potential for the development of point-of-care diagnostic devices.