Anhui University

Polarity, viscosity and peroxynitrite (ONOO^-) are key factors in determining mitochondrial function and activity, and real-time monitoring of these parameters is important for gaining insight into the physiological mechanisms involved. In this study, we developed a new multifunctional fluorescent probe CNB-2 for monitoring mitochondrial polarity, viscosity, and ONOO^- level fluctuations. CNB-2 demonstrated robust responses to polarity and viscosity, with its fluorescence intensity exhibiting a strong linear correlation to the logarithm of polarity parameters and viscosity, increasing significantly as these parameters rise. Notably, for ONOO^- detection, CNB-2 is characterized by rapid response, high selectivity, a low detection limit (51.3 nM), and a large Stokes shift (130 nm). Moreover, CNB-2 can be used for live cell imaging of mitochondrial polarity, viscosity, and ONOO^-, as well as monitoring of changes in ONOO^- concentration in real-time during ferroptosis. Therefore, the prepared probe CNB-2 provides a reliable tool for better understanding the mitochondrial microenvironment and a new way for diagnosing ferroptosis-related diseases.

Development of NIR type I photosensitizers (PSs) that can specifically target subcellular organelles remains a significant challenge in photodynamic therapy (PDT). In this work, two D-π-A PSs named TPE-IN and TPA-IN were constructed via the strategy of changing donors. In detail, replacing donor group tetraphenylethylene (TPE-IN) with triphenylamine (TPA-IN) could extend the emission wavelength of PSs into the NIR-I region. Meanwhile, the singlet-triplet energy gap (ΔE_ST = 0.53 eV) of PSs was also narrowed, which efficiently promoted the production of superoxide anion radical (O₂^-) and hydroxyl radical (OH), especially for TPA-IN. Further mechanistic studies demonstrated that the generation of OH mainly relied on the cascaded electron-transfer process mediated by the Haber-Weiss reaction (O₂^- → H₂O₂ → OH). More importantly, TPA-IN could specifically accumulate in mitochondria through electrostatic interactions (Pr = 0.81), which could decrease mitochondrial membrane potential, inducing cell late apoptosis (95.8 %) upon light exposure. This study established innovative theoretical and technological groundwork for designing high-efficiency, precision-targeted optical theranostic agents aimed at eliminating cancer cells.

Multifunctional temperature/pressure sensors have garnered significant research interest due to their broad applicability in wearable electronics and health monitoring. Nevertheless, most pressure sensors often exhibit pronounced nonlinear responses, primarily attributed to the pressure-dependent increase in compressive modulus. In this paper, we report a multifunctional sensor with ultra-high linearity pressure and well- temperature-sensing performance, fabricated via a facile dip-coating process. The hydrogen bonding interaction between carboxymethyl cellulose (CMC) and MXene effectively mitigates the self-stacking tendency of MXene (Ti₃C₂T_x) nanosheets. Subsequently, the CMC-modified MXene facilitates the conformational transition of PEDOT (Poly (3,4-ethylenedioxythiophene)) chains from benzoid to quinoid structures. This synergistic effect enables the fabrication of composites with enhanced electromechanical performance. Additionally, an innovative alternating current (AC) measurement is employed to investigate the potential resistance-capacitance hybrid response within the sensors. By optimizing preparation parameters, we achieve an ultra-high linearity (R² = 0.9943) across a broad detection range, alongside a well temperature sensitivity (-2.3575 %/°C). Proof-of-concept applications, including quilt slippage detection and pressure ulcer prevention, demonstrate the sensor's multifunctional capabilities. These findings highlight its potential for wearable medical devices and real-time health monitoring.