Monitoring disease-implicated hydrogen sulfide in blood using a facile deproteinization-based electrochemiluminescence chemosensor system
Yecheol Bak, Tikum Florence Anjong, Ji Hwan Park, Sang Hyeon Jeon, Ji‐Hwan Kim, Kangwon Lee, Ik‐Soo Shin, Sehoon Kim
Abstract
Hydrogen sulfide (H2S), an antioxidant and cell signaling molecule, plays a critical role in redox reactions in the biological system, and its imbalances in blood levels have been implicated in various diseases. Here, we demonstrate a novel chemosensor-based “turn-on” electrochemiluminescence (ECL) system for the selective and sensitive detection of H2S in a type 1 diabetes rat model. Our luminogenic chemosensor (Probe) is a redox-stable cyclometalating iridium (III) complex with emission-quenching 2,4-dinitrophenyl ether (DNP) that shows a significant enhancement in emission intensity upon cleavage of DNP by selective reaction towards H2S. To achieve robust and reliable ECL emission of Probe for biological analysis, we developed a facile deproteinization protocol based on organic solvent-induced protein precipitation/syringe filtration that eliminates uncontrolled protein adsorption on the electrode surface from protein-rich biological samples. Our deproteinization-assisted ECL chemosensor system showed effectiveness in detecting disease-associated H2S levels in biological media with a linear response in the range of 0–250 µM (R2: 0.992). It enables reliable in vitro monitoring of H2S level changes in blood samples of a type 1 diabetes rat model (P = 0.0296). This strategy to integrate chemosensor-based ECL and facile deproteinization protocol provides a sensitive and rapid disease-monitoring platform for detecting small-molecule biomarkers.