Sperm quality assessment is critical for the diagnosis of male infertility. However, conventional methods mainly focus on kinematic parameters and fail to real-time monitor the dynamic intracellular microenvironment of sperm. Single-parameter detection also suffers from insufficient sensitivity and specificity under complex interference, making it difficult to accurately identify functionally impaired sperm. Herein, we designed and synthesized two near-infrared fluorescent probes, QSi-BA and QSi-OBA, based on silicon-xanthene scaffolds via a one-step modification. QSi-OBA shows a remarkable synergistic fluorescence enhancement response to acidic and high-viscosity microenvironments, together with high photostability and excellent anti-interference ability. The probe enables wash-free, real-time imaging of dynamic microenvironmental changes in human sperm. Using drug-induced stimulation models, we verified its capability to monitor pH and viscosity perturbations. More importantly, QSi-OBA can effectively distinguish asthenospermic sperm from healthy samples, without relying on normal routine semen parameters. This probe provides a powerful and reliable molecular imaging tool for precise sperm function evaluation, auxiliary diagnosis of male infertility, and related reproductive pathological studies.
Zhang et al. (Mon,) studied this question.