Electrochemiluminescence sensor for point-of-care detection of pyrrolizidine alkaloids

Pyrrolizidine alkaloids (PAs) and PA N-oxides are hepatotoxic natural products, produced by over 6000 plant species worldwide. However, an unmet need remains for confirmative measurement of PAs in routine clinical tests. Here, we develop a visual, easy-to-use, and economic mesoporous silica-electrochemiluminescence (MPSECL) sensor for point-of-care (POC) testing of PAs, utilizing MPS's amplification effect on positive ions. The relationship between PAs' different structures and corresponding Ru(bpy)(3)(2+) ECL activity shows that reaction mechanism, stability of intermediate, molecular geometry and alternative anodic reactivity significantly affect the ECL activity. The ECL intensity varies among different PAs: monocrotaline > senecionine N-oxide > retrorsine > senkirkine. The POC sensors possess excellent linearity (0.9993 > R-2 > 0.9944), low detection limits (0.02 mu M-0.07 mu M), and good recoveries (90.12%-105.93%), indicating good accuracy and practicability. The portable and low-cost sensor is user-friendly, which holds promise to be applied to POC testing of PAs in drugs, food products, and clinical samples, which is promising for initial assessments of PA-induced health risk.