Development of\nan Activity-Based Ratiometric Electrochemical\nSwitch for Direct, Real-Time Sensing of Pantetheinase in Live Cells,\nBlood, and Urine Samples

Pantetheinase is\na key biomarker for the diagnosis of\nacute kidney\ninjury and the monitoring of malaria progression. Currently, existing\nmethods for sensing pantetheinase, also known as Vanin-1, show considerable\npotential but come with certain limitations, including their inability\nto directly sense analytes in turbid biofluid samples without tedious\nsample pretreatment. Here, we describe the first activity-based electrochemical\nprobe, termed VaninLP, for convenient and specific direct targeting\nof pantetheinase activity in turbid liquid biopsy samples. The probe\nwas designed such that cleavage of the pantetheinase amide linkage,\ntriggered by a self-immolative reaction, simultaneously ejects an\namino ferrocene reporter. Among the distinctive properties of the\nVaninLP probe for sensing pantetheinase are its high selectivity,\nsensitivity, and enzyme affinity, a wide linear concentration range\n(8–300 ng/mL), and low limit of detection (2.47 ng/mL). The\ndesigned probe precisely targeted pantetheinase and was free of interference\nby other electroactive biological species. We further successfully\napplied the VaninLP probe to monitor and quantify the activity of\npantetheinase on the surfaces of HepG2 tumor cells, blood, and urine\nsamples. Collectively, our findings indicate that VaninLP holds significant\npromise as a point-of-care tool for diagnosing early-stage kidney\ninjury, as well as monitoring the progression of malaria.