Facile Mechanophore Integration in Heterogeneous Biologically Derived Materials via "Dip-Conjugation"

Mechanical forces play critical roles in a wide variety of biological processes and diseases, yet measuring them directly at the molecular level remains one of the main challenges of mechanobiology. Here, we show a strategy to "Dip-conjugate" biologically derived materials at the chemical level to mechanophores, force-responsive molecular entities, using Click-chemistry. Contrary to classical prepolymerization mechanophore incorporation, this new protocol leads to detectable mechanochromic response with as low as 5% strain, finally making mechanophores relevant for many biological processes that have previously been inaccessible. Our results demonstrate the ubiquity of the technique with activation in synthetic polymers, carbohydrates, and proteins under mechanical force, with alpaca wool fibers as a key example. These results push the limits for mechanophore use in far more types of polymeric materials in applications ranging from molecular-level force damage detection to direct and quantitative 3D force measurements in mechanobiology.