Tuning Electrochemiluminescence in Multistimuli Responsive Hydrogel Films

Area of Science:

• Materials Science
• Electrochemistry
• Biomaterials

Background:

• Stimuli-responsive hydrogels offer tunable properties for advanced applications.
• Integrating sensing and luminescent functionalities enhances material capabilities.
• Smart materials are crucial for developing novel biosensors and bioelectronic devices.

Purpose of the Study:

• To design and characterize a novel hydrogel with multistimuli responsive electrochemical and luminescent switching behaviors.
• To investigate the interplay between stimuli-induced swelling/collapse and electrogenerated chemiluminescence (ECL).
• To explore the potential of these hydrogels in biosensing and bioelectronic applications.

Main Methods:

• Synthesis of a poly(N-isopropylacrylamide) hydrogel matrix incorporating phenylboronic acids and [Ru(bpy)₃]²⁺ luminophores.
• Sequential application of stimuli (fructose and temperature) to induce swelling and collapse.
• Electrochemical and luminescent measurements to evaluate material response.

Main Results:

• The hydrogel exhibited reversible redox activity modulated by sequential stimuli.
• Electrogenerated chemiluminescence (ECL) showed a significant enhancement (∼16-fold) upon temperature-induced collapse.
• Fructose-induced swelling led to a decrease in light emission, demonstrating stimulus-dependent luminescence modulation.
• ECL response was found to correlate intrinsically with the swelling ratio and modulated by both stimuli.

Conclusions:

• The developed hydrogel demonstrates intrinsic correlation between ECL and swelling ratio, finely modulated by temperature and fructose.
• These multistimuli responsive ECL-active hydrogels hold promise for biosensing, novel luminescent materials, and logic gates in bioelectronic devices.