¹⁹F magnetic resonance imaging (¹⁹F MRI) is a promising technique for in vivo molecular imaging and clinical diagnosis, benefiting from its negligible background and unlimited tissue penetration depth. However, the development of ¹⁹F probes with good water solubility and versatile functions for bioresponsive and practical applications remains a challenge. Here, we report fluorinated ion liquids (ILs) as a new type of fluorine agents and build a fluorinated ionic liquid-based activatable ¹⁹F MRI platform (FILAMP), which relies on the phase transition of ILs. Upon exposure to environmental stimulation, coating polymer dissolves or degrades to release the fluorinated ILs payload, which rapidly enhances ¹⁹F signal. This “turn-on” response is verified by the successful detection of biological targets (for example, dysregulated pH and MMP overexpression) at the cellular level and in mice, demonstrating the potential of FILAMP as a robust activatable ¹⁹F probe for diagnosis and monitoring of biological and pathological processes.

¹⁹ F磁共振成像（¹⁹ F MRI）受益于其可忽略的背景和无限的组织穿透深度，是一种用于体内分子成像和临床诊断的有前途的技术。然而，开发具有良好水溶性和多功能功能的¹⁹ F探针以用于生物响应和实际应用仍然是一个挑战。在这里，我们报告氟化离子液体（ILs）作为一种新型的氟剂，并建立一个基于ILs相变的基于氟化离子液体的可激活¹⁹ F MRI平台（FILAMP）。暴露于环境刺激下，涂料聚合物溶解或降解以释放氟化的ILs有效负载，从而迅速提高¹⁹F信号。通过在细胞水平和小鼠中成功检测到生物学目标（例如，失调的pH和MMP过表达），验证了这种“开启”响应，证明了FILAMP作为一种强大的可激活的¹⁹ F探针进行诊断和监测的潜力生物和病理过程。