Fluorescent solid-state strips based on SiO 2 shell-stabilized perovskite nanocrystals applying for magnetic aptasensing detection of aflatoxin B 1 toxin in food.

In this work, the perovskite fluorescent nanocrystals (CsPbBr3 ) were successfully synthesized and wrapped with SiO2 shell, utilized for the assembly of solid-state detection strip capable of conveniently and specifically detection of aflatoxin B1 (AFB1 ). The SiO2 coating aimed to enhance the stability of CsPbBr3 nanocrystals. The resulting CsPbBr3 @SiO2 material exhibited remarkable fluorescence properties, and further self-assembled onto solid-state plate, generating AFB1 -specific quenched fluorescence at a specific wavelength of 515 nm. When combined with the capture of AFB1 by magnetic nanoparticles conjugated with aptamers (MNPs-Apt), it was achieved the good separation and specific detection of AFB1 toxin in food matrices. The constructed fluorescent solid-state detection strip based on CsPbBr3 @SiO2 exhibited good response to AFB1 toxin within a linear range of 0.1-100 ng mL-1 and an impressive detection limit as low as 0.053 ng mL-1 . This presents a new strategy for the rapid screening and convenient detection of highly toxic AFB1 .