A novel near-infrared probe for the imaging of superoxide anion fluctuations and hydrogen ion enhancement in vivo

Abstract

Superoxide anions (O₂˙⁻) and hydrogen ions (H⁺) have attracted considerable attention in studies on cellular dysfunction. A newly synthesized reaction-based near-infrared imaging probe (IR-747-SAPH), which is composed of a superoxide anion responsive group and a H⁺ responsive group, exhibits high selectivity to O₂˙⁻ and H⁺ fluxes in vivo. The fluorescence intensity of IR-747-SAPH changes as O₂˙⁻ and H⁺ concentrations vary. IR-747-SAPH is characterized by sensitivity to changes in H⁺, high photostability, and strong near-infrared properties, including high temporal resolution, deep penetration, and low background interference. The probe also provides reliable near-infrared fluorescence signals that alter O₂˙⁻and H⁺ levels in vivo. Therefore, IR-747-SAPH fluorescence imaging is a promising detection method for monitoring the changes in O₂˙⁻ and H⁺ in various biological environments.