Using green emitting pH-responsive nanogels to report environmental changes within hydrogels: a nanoprobe for...

Area of Science:

• Materials Science
• Biotechnology
• Spectroscopy

Background:

• Photoluminescence (PL) spectroscopy is valuable for studying hydrogel environments.
• Current methods often require time-consuming synthesis of custom fluorophores, potentially leaving toxic residues.
• A more versatile approach involves using pre-formed nanogel probes with donor/acceptor pairs.

Purpose of the Study:

• To introduce and validate novel green-emitting methacrylic acid-based nanogel probes.
• To demonstrate their utility in reporting local environments within various gels and stem cells.
• To establish these nanoprobes as a viable alternative to custom fluorophore labeling.

Main Methods:

• Development of green-emitting methacrylic acid-based nanogel probe particles.
• Incorporation of nanogel probes into different gel matrices and stem cells during assembly.
• Monitoring changes in non-radiative energy transfer efficiency via PL ratiometric intensity.

Main Results:

• Nanogel probes successfully reported local environmental changes within four different gels and stem cells.
• Non-radiative energy transfer efficiency within nanoprobes correlated with gel swelling.
• Reversible reporting of gel swelling changes induced by divalent cations, degradation, pH, temperature, and tensile strain.
• Nanocomposite gels exhibited mechanochromic behavior when incorporating the nanoprobes.

Conclusions:

• The developed green-fluorescing nanoprobes offer a sensitive and reversible method for reporting internal gel environments.
• They provide valuable structural insights into hierarchical natural and synthetic gels.
• These nanoprobes present a practical and safer alternative to custom fluorophore labeling for diverse applications.