Ratiometric dynamic mechano- and radioluminescence for self-referencing mechanical sensing and X-ray dosimetry

Luminescent materials enable effective transduction of external stimuli via changes in intensity, lifetime, or emission spectrum. However, conventional single-parameter detection suffer from limited reliability under environmental fluctuations. To address this, ratiometric luminescent sensing with intrinsic self-referencing mechanisms have been developed to enhance robustness. In this work, a multifunctional luminescent platform was established by embedding Mn 2+ /Cr 3+ co -doped SrGa 12 O 19 (SGO) phosphors into a polydimethylsiloxane (PDMS) matrix (SGO: Cr 3+ ,Mn 2+ @PDMS). This composite exhibits triboelectricity-induced mechanoluminescence (ML) under mechanical stimuli, with emission intensity correlating with applied strain. Distinct mechanical sensitivities of Mn 2+ and Cr 3+ enable a ratiometric ML response in the 25%–50% deformation range, achieving self-referenced mechanical sensing. Under X-ray irradiation, a trap-assisted ratiometric radioluminescence (RL) phenomenon emerges, governed by the dynamic interplay between charge traps and luminescent centers. Comparative studies with ultraviolet (UV)-excited luminescence confirm a unified mechanism wherein trapped carriers are gradually populated and subsequently redistributed among multiple emission centers, producing a tunable and dynamic luminescence profile. Together, these findings demonstrate the feasibility of integrating ratiometric detection for both mechanical and radiation stimuli within a single material system. This work offers a novel approach toward the development of next-generation multifunctional optical sensors for deployment in complex or variable environments.