Scintillon-Mimicking Mechanoluminescence for Theranostic Applications

Mechanoluminescence offers unique advantages over traditional photoluminescence, including deeper tissue penetration and minimal autofluorescence. However, mechanoluminescent materials typically lack the sensitivity and reusability of their biological counterparts. Inspired by the mechanoregulation of luciferase in dinoflagellate scintillons, we develop a scintillon-mimetic mechanoluminescent nanoreactor (sMLN) by integrating mechanoresponsive ferrocene (Fc) moieties into a flexible organic silica vesicle. Under ultrasound (US) irradiation, acoustic shear forces stretch and twist the Fc moiety, increasing the Fe center electron density and reducing steric hindrance, thereby facilitating substrate binding and activating a Fenton-like reaction that triggers luminol-based luminescence. Unlike conventional mechanoluminescent materials, sMLNs exhibit repeatable and long-lasting luminescence with a half-life of approximately 5.73 min, leading to a ∼2.2 × 10³-fold enhancement in intensity compared to H₂O sonoluminescence. This US-induced mechanoluminescence functions as an "internal light source" to excite the chromophore for bioimaging and photodynamic therapy, overcoming the limitations of light penetration depth. This high-performance platform enables intense and ultrasensitive mechanoluminescence, providing a powerful mechanochemical tool for advanced theranostic applications.