H₂O₂ responsive rhodamine-based probe for monitoring early-stage diabetes diagnosis

Hydrogen peroxide (H₂O₂) is a crucial member of the reactive oxygen species (ROS) family, playing roles in cellular signalling and immune responses in human health. Moreover, it is a potential biomarker of diabetes when present in aberrant concentrations. Therefore, monitoring trace levels of H₂O₂ has become a research hotspot for analytical and sensor chemists. In this context, we report a rhodamine-based fluorescent probe (RN), which shows excellent fluorescent enhancement at 555 nm upon the addition of H₂O₂ along with a low limit of detection (LOD) of 0.67 ppm and fast response (∼2 min). The probe is highly selective for H₂O₂, showing no fluorescence enhancement with other ROS. RN is synthesised in a one-pot chemical reaction using rhodamine 6G (R6G) and 4,7,10-trioxa-1,13-tridecanediamine (TTDA). H₂O₂ detection in pre-treated milk samples proves its real-world viability. We found that RN shows low cytotoxicity, which allowed us to successfully explore its potential to monitor H₂O₂ generation in a diabetic L929 skin cell line and diabetic mice liver tissue. This result demonstrates promising features for assessing early diabetic progression through fluorescence imaging.