Surface-Enhanced Raman Spectroscopy-Based Label-Free Insulin Detection at Physiological Concentrations for Analysis...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Endocrinology

Background:

• Accurate insulin detection is crucial for understanding pancreatic cell function and diabetes.
• Existing methods often require labels or lack sensitivity at physiological concentrations.

Purpose of the Study:

• To develop a label-free optical detection method for insulin in pancreatic islet secretions.
• To assess pancreatic cell function under varying glucose conditions without altering their natural state.

Main Methods:

• Utilized spatially uniform 3D gold nanoparticle sensors for surface-enhanced Raman sensing.
• Measured insulin in human pancreatic islet secretions under low and high glucose environments.
• Analyzed Raman emission intensities correlated with glucose levels and insulin concentrations.

Main Results:

• Achieved sensitive and reliable label-free insulin detection down to 100 pM.
• Demonstrated a dynamic range of 100 pM to 50 nM with a 35 pM detection limit.
• Showcased a 4-order-of-magnitude increase in sensitivity compared to previous label-free optical methods.

Conclusions:

• The developed sensor enables label-free, cost-effective insulin detection for in vitro pancreatic cell assessment.
• This technology holds promise for advancing diabetes research and clinical applications.
• The method provides a sensitive and reliable tool for monitoring insulin secretion dynamics.