Homogeneous electrochemiluminescence sensor based on novel Ru-MOF nanosheets for highly sensitive and efficient detection of glutathione without immobilization

Abstract

Glutathione (GSH), a key antioxidant, plays a crucial role in maintaining redox balance and other essential physiological functions in the body. Electrochemiluminescence (ECL) technology holds great potential for GSH detection due to its excellent performance. However, most existing ECL probes rely on heterodyne detection, where the probe must be immobilized on the electrode surface. This approach not only limits detection to the solid–liquid interface, thereby affecting identification efficiency, but also risks probe detachment or reduced activity due to instability during the immobilization process, which in turn compromises sensitivity and accuracy. These limitations make heterodyne detection challenging in practical applications, highlighting the need for improvements and innovation. In this study, we synthesized a water-soluble ECL probe using tris(2,2′-bipyridine)ruthenium (Ru(dcbpy)₃²⁺)-functionalized metal–organic frameworks (RuMOFNSs), enabling efficient and reliable GSH detection under homogeneous conditions. The experimental results demonstrated that the probe exhibited excellent sensitivity and selectivity across a concentration range from 10 mM to 10 pM, with a detection limit as low as 0.57 pM, and was able to achieve a rapid response within 5 min. In addition, the sensor showed excellent performance in analysis of real human serum samples. In this study, an ultrasensitive ECL sensing system for GSH detection based on MOF materials is proposed for the first time and provides an effective method for the monitoring of diseases related to GSH levels in the clinic.

Graphical abstract