Amperometric S-nitrosothiol sensor with enhanced sensitivity based on organoselenium catalysts

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Biochemistry

Background:

• S-nitrosothiols (RSNOs) are crucial signaling molecules involved in various physiological processes.
• Dysregulation of RSNO levels is linked to endothelial dysfunction and cardiovascular diseases.
• Accurate and rapid detection of RSNOs in biological samples remains a challenge.

Purpose of the Study:

• To develop and characterize a novel electrochemical sensor for the rapid and sensitive detection of total S-nitrosothiols (RSNOs) in biological samples.
• To assess the sensor's performance in whole blood, including its selectivity and stability.
• To demonstrate the sensor's utility for both low-molecular-weight (LMW) and macromolecular RSNOs.

Main Methods:

• Development of an electrochemical sensor utilizing a cellulose dialysis membrane modified with an organoselenium catalyst.
• Covalent modification of the membrane to facilitate the conversion of RSNOs to nitric oxide (NO).
• Amperometric detection of NO at the sensor's tip, coupled with a standard addition method for quantification in whole blood.

Main Results:

• The developed sensor demonstrated very low detection limits (<20 nM) for RSNOs.
• The sensor exhibited excellent long-term stability and high selectivity against nitrosamines and nitrite.
• The method successfully quantified total RSNO levels in whole blood, including both LMW and macromolecular forms.

Conclusions:

• The novel electrochemical sensor provides a rapid, sensitive, and selective method for total RSNO detection in blood.
• This technology has the potential to advance research into the role of RSNOs in endothelial dysfunction and cardiovascular diseases.
• The sensor's ability to detect both LMW and macromolecular RSNOs offers a comprehensive approach to assessing redox status in biological systems.