Acid-promoted fluorescent probe for monitoring endogenous methylglyoxal in tumors and gastritis

Methylglyoxal (MGO) is an important dicarbonyl metabolite that plays a crucial role in a range of physiological and pathological processes. It is critical to develop precise methods for detecting MGO levels in vivo to better understand its role in disease progression. Herein, we report an MGO-activatable fluorescent probe Cy-DNH2 based on hemicyanine, which could rapidly and selectively detect MGO with a low LOD of 95 nM in an acidic microenvironment. In the presence of MGO, acidic pH could trigger Cy-DNH2 to turn on intense fluorescence within 3 min. Moreover, Cy-DNH2 was able to target lysosomes, allowing for the detection of endogenous MGO in living cells as well as the identification of elevated MGO levels in tumors and mouse models of gastritis. This work may provide a valuable tool for monitoring MGO under acidic conditions and diagnosing MGO-related diseases. An acid-promoted "turn-on" fluorescent probe is reported for real-time detection of methylglyoxal in tumors and gastritis with high sensitivity and selectivity.