Bio-Inspired Carbon Monoxide Sensors with Voltage-Activated Sensitivity

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Sensing

Background:

• Carbon monoxide (CO) poisoning occurs when CO outcompetes oxygen for hemeprotein binding.
• Iron porphyrins exhibit a strong, specific interaction with CO, forming the basis for selective sensors.
• Existing CO sensors require further development for enhanced sensitivity and selectivity.

Purpose of the Study:

• To develop novel chemiresistive sensors for carbon monoxide (CO) detection.
• To investigate voltage-activated sensitivity using iron porphyrin and functionalized single-walled carbon nanotubes (F-SWCNTs).
• To explore the role of redox state in CO-F-SWCNT interaction.

Main Methods:

• Fabrication of chemiresistive sensors with iron porphyrin and F-SWCNTs.
• Application of modulated gate voltage for sensing.
• Characterization using UV/Vis spectroscopy, differential pulse voltammetry, and density functional theory (DFT).

Main Results:

• Sensors demonstrated significantly increased sensitivity to CO under negative gate voltage.
• The developed dosimetric sensors showed selectivity for ppm levels of CO in air.
• In situ reduction of Fe(III) to Fe(II) was found to enhance CO interaction with F-SWCNTs.

Conclusions:

• Voltage modulation provides an additional dimension for tuning sensor performance.
• Redox-activated recognition units offer a new strategy for highly specific and enhanced CO sensing.
• These findings pave the way for advanced, voltage-controlled gas sensors.