LAUSR

Luminol is a classic electrochemiluminescence (ECL) luminophore. The luminol-O2 ECL system suffers from a problem, that is, the conversion rate of dissolved O2 into reactive oxygen species (ROS) is low. In this work, we used high-intensity focused ultrasound (HIFU) pretreatment combined with Ti3C2-TiO2 to construct a highly sensitive luminol-O2 ECL system for the specific detection of polynucleotide kinase (PNK) first. On the one hand, HIFU generated ROS in situ as a coreactant via the cavitation effect to boost the luminol emission. On the other hand, Ti3C2-TiO2 was prepared in situ via Ti3C2 as a reducing agent, and it can aggregate and catalyze ROS generated in situ by HIFU. Moreover, the Ti on the Ti3C2-TiO2 surface could bind to phosphate groups through chelation, thereby realizing highly specific detection of PNK. The sensor has a linear relationship range of 1.0 × 10-5 to 10.0 U mL-1, and the limit of detection is 1.48 × 10-7 U mL-1, which is superior to most existing methods. The sensor performance in HeLa cell lysate was measured with a satisfactory result. The designed ECL biosensor has potential applications in biological analysis and clinical diagnosis.