Nanoparticle-based paper sensor for thiols evaluation in human skin

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Thiols, particularly glutathione, play vital roles in skin health and oxidative stress.
• Current methods for thiol detection in skin can be invasive or lack sensitivity.
• Development of a sensitive, non-invasive method for skin thiol analysis is needed.

Purpose of the Study:

• To develop and validate a novel, sensitive, and non-invasive gold nanoparticle-based sensor for detecting thiols in human skin.
• To establish the analytical performance of the sensor using glutathione as a model biothiol.
• To assess the sensor's applicability for in vivo skin thiol level determination.

Main Methods:

• A gold nanoparticle-based paper sensor was designed, utilizing color change upon thiol-induced aggregation for detection.
• The analytical response was quantified by the ratio of blue to red color intensity in RGB images.
• Glutathione was used as a model biothiol to determine linearity range, detection limit, precision, and recovery.
• Interference studies were conducted with common skin matrix components.

Main Results:

• The sensor demonstrated a linear range of 8-75µM and a detection limit of 6.9µM for glutathione.
• Inter-day and intra-day precision showed relative standard deviations (RSD) of ≤7% and ≤12%, respectively.
• Recovery rates for glutathione spiked onto skin ranged from 77-138%.
• Common skin components showed no significant interference at specified concentrations.
• In vivo measurements on volunteers revealed skin thiol levels between 11.6-47.5µM.

Conclusions:

• The developed gold nanoparticle sensor offers a sensitive and non-invasive approach for detecting thiols in human skin.
• The sensor exhibits good analytical performance and specificity, suitable for monitoring skin's thiol status.
• This technology holds potential for non-invasive diagnostics and health monitoring related to skin oxidative stress.