One-step assay of pore-forming biotoxins based on biomimetic perovskite nanocrystals

Abstract As one of the emerging inorganic materials, perovskite nanocrystals (NCs) have inspired the development of various optoelectronic applications in recent years; however the effective utilization in biomedical fields is still limited. Herein, we report a quantitative measurement of broad-spectrum pore-forming toxins in complex media based on biomimetic CsPbBr3 NCs. Specifically, by coating CsPbBr3 NCs with phospholipid (CsPbBr3 NCs@PL), the outer micelle membrane can not only serve as a shell to protect the stability of CsPbBr3 NCs, but also interact with broad-spectrum biotoxins. Meanwhile, toxin-triggered transmembrane pore formation can cause water permeation, which breaks down the structure of CsPbBr3 NCs@PL, generating striking fluorescent and electrochemical dual responses. Therefore, direct quantitative measurements of biotoxins are realized via dual-readout signals with inverse change trend, resulting in a detection limit of 50 nM. Our report represents the first example of CsPbBr3 NCs for the develpment of biosensors. Meanwhile, such a label-free, cost-effective and widely applicable biomimetic CsPbBr3 NCs@PL may present a valuable tool for the detection of biotoxin infections, and overcomes the limitations of perovskite materials in biosensing.