Amperometric nitric oxide microsensor based on nanopore-platinized platinum: the application for imaging NO...

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Nitric oxide (NO) plays crucial roles in biological systems, necessitating accurate detection methods.
• Microsensors offer high spatial resolution for localized NO measurements.
• Existing NO sensors face challenges in sensitivity, selectivity, and response time.

Purpose of the Study:

• To develop and characterize a novel amperometric nitric oxide (NO) microsensor.
• To enhance sensor performance through nanopore fabrication and electrochemical platinization.
• To evaluate the sensor's utility in scanning electrochemical microscopy (SECM) for NO imaging.

Main Methods:

• Fabrication of a cone-shaped nanopore-platinized Pt working electrode.
• Electrochemical etching to create a nanopore structure.
• Electrochemical platinization and silanization for improved sensitivity and selectivity.
• Modification with poly(5-amino-1-naphthol) for NO selectivity.
• Performance characterization including dynamic range, detection limit, response time, and sensitivity.
• Application as a probe tip in SECM for 2D NO imaging.

Main Results:

• The microsensor exhibited a linear dynamic range of 0.2-1.8 microM.
• A low detection limit of < approximately 32 nM was achieved.
• Rapid response time (t(90%)) of < approximately 5 s was observed.
• High sensitivity of 6.5 +/- 0.02 pA/nM was determined.
• Successful application in SECM for 2D imaging of local NO concentrations.

Conclusions:

• The developed cone-shaped nanopore-platinized Pt microsensor is a sensitive and selective probe for NO.
• The sensor's performance characteristics are suitable for electrochemical applications.
• The microsensor enables effective 2D imaging of NO distribution using SECM.