Rotaxane Probes for the Detection of Hydrogen Peroxide by ¹²⁹Xe HyperCEST NMR Spectroscopy

Abstract

The development of sensitive and chemically selective MRI contrast agents is imperative for the early detection and diagnosis of many diseases. Conventional responsive contrast agents used in ¹ H MRI are impaired by the high abundance of protons in the body. ¹²⁹ Xe hyperCEST NMR/MRI comprises a highly sensitive complement to traditional ¹ H MRI because of its ability to report specific chemical environments. To date, the scope of responsive ¹²⁹ Xe NMR contrast agents lacks breadth in the specific detection of small molecules, which are often important markers of disease. Herein, we report the synthesis and characterization of a rotaxane-based ¹²⁹ Xe hyperCEST NMR contrast agent that can be turned on in response to H₂ O₂ , which is upregulated in several disease states. Added H₂ O₂ was detected by ¹²⁹ Xe hyperCEST NMR spectroscopy in the low micromolar range, as well as H₂ O₂ produced by HEK 293T cells activated with tumor necrosis factor.