Highly Sensitive Surface-Enhanced Raman Scattering Detection of Hydroxyl Radicals in Water Microdroplets Using...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Atmospheric Science

Background:

• Spontaneous hydrogen peroxide (H2O2) generation in atmospheric microdroplets influences pollutant degradation and oxidative stress.
• Quantifying hydroxyl radicals (•OH), key to H2O2 formation, is difficult due to their short lifetime and low concentrations.

Purpose of the Study:

• To develop a sensitive and selective nanosensor for quantifying •OH in water microdroplets.
• To enable accurate measurement of •OH for atmospheric H2O2 formation studies.

Main Methods:

• Utilized a phthalhydrazide (Phth) probe with surface-enhanced Raman scattering (SERS) for •OH detection.
• Designed a SERS nanosensor for analyzing microdroplets, ensuring rapid and interference-free measurements.

Main Results:

• Achieved a linear detection range for •OH from 2 nM to 2 μM.
• Established a limit of detection as low as 0.34 nM for •OH.
• Demonstrated sensor robustness and accuracy in water microdroplets.

Conclusions:

• The developed SERS nanosensor provides a powerful tool for quantifying •OH in atmospheric microdroplets.
• This method facilitates mechanistic studies of H2O2 generation in the atmosphere.
• The findings contribute to understanding atmospheric H2O2 impacts on air quality and pollutant degradation.