The Preparation of an Optical Hydrogen Peroxide Sensor Using Polydopamine as a Sensing Medium

Area of Science:

• Materials Science
• Biomedical Engineering
• Analytical Chemistry

Background:

• Polydopamine (PDA) is a versatile coating material known for biocompatibility, biodegradability, and stability.
• Dopamine (DA) itself lacks fluorescence, limiting its direct application in optical sensing.

Purpose of the Study:

• To develop an in situ method for creating fluorescent polydopamine (PDA).
• To fabricate a novel hydrogen peroxide (H₂O₂) sensor utilizing fluorescent PDA.
• To evaluate the sensor's performance for potential in vivo applications.

Main Methods:

• In situ preparation of fluorescent PDA by oxidizing dopamine (DA) with hydrogen peroxide (H₂O₂) in the presence of Cu²⁺.
• Fabrication of a fluorescence-based H₂O₂ sensor using the synthesized PDA.
• Characterization of PDA fluorescence properties and sensor performance, including sensitivity and detection limit.

Main Results:

• In situ synthesized PDA exhibited strong fluorescence at 480 nm (excitation 330–420 nm) due to DA oxidation by H₂O₂.
• The fabricated H₂O₂ sensor demonstrated high sensitivity and a linear response.
• A low detection limit of 0.7 μM for H₂O₂ was achieved.

Conclusions:

• A novel, fluorescent PDA material was successfully synthesized in situ.
• The PDA-based sensor is highly sensitive and exhibits excellent linear response for H₂O₂ detection.
• The sensor's non-toxic and biodegradable nature makes it promising for in vivo applications.