Ultrastable Luminol-OH^--(Ni-WO-CNT) ECL System with High Strength and Its Applications in Sensing

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Traditional luminol electrochemiluminescence (ECL) relies on hydrogen peroxide (H₂O₂) or dissolved oxygen (DO) as coreactants.
• H₂O₂ self-decomposition and limited oxygen solubility/content restrict luminol ECL efficiency and stability.
• Reactive oxygen species (ROS) play a key role in ECL mechanisms.

Purpose of the Study:

• To develop an advanced luminol ECL coreactant using hydroxide ions (OH⁻) and a novel catalyst.
• To improve luminescence intensity and stability compared to existing systems.
• To demonstrate the system's versatility for various biosensing applications.

Main Methods:

• Utilized nickel-doped and carbon nanotube-modified tungsten oxide (Ni-WO-CNT) as a coreactant accelerator.
• Generated ROS from OH⁻ at low excitation voltage using the Ni-WO-CNT catalyst.
• Employed traditional three-electrode and closed bipolar electrode systems for sensing.

Main Results:

• Achieved high luminescent intensity (85,563 a.u.) and exceptional stability over 1300 tests.
• Outperformed luminol-H₂O₂ and luminol-DO systems in both intensity and stability.
• Successfully monitored uric acid (UA), C-reactive protein (CRP), immunoglobulin G (IgG), and glucose (Glu) using diverse sensing strategies.

Conclusions:

• Hydroxide ions, accelerated by Ni-WO-CNT, offer a superior alternative coreactant for luminol ECL.
• The developed ROS-mediated ECL system exhibits remarkable intensity and stability.
• The system demonstrates broad applicability and potential for advanced biosensor development.