CoOOH nanosheets ensure ratiometric fluorescence assay of acetylcholinesterase

• Published in: Talanta (Oxford) Vol. 249; p. 123664
• Main Authors: Zhang Wang Xu Yang Shu, Xiao-Ping, Wang, Jian-Hua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2022
• Subjects: Acetylcholinesterase; CoOOH nanosheets; Peroxidase-like activity; Ratiometric; CoOOH nanosheets; Peroxidase-like activity; Acetylcholinesterase; Ratiometric
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123664

Cobalt oxyhydroxide nanosheets (CoOOH) with peroxidase-like activity provide a promising probe for acetylcholinesterase (AChE) sensing through a ratiometric fluorescence strategy. Fluorescence of silicon quantum dots (SiQDs) at 457 nm was quenched by CoOOH on account of inner-filter effect (IFE). Meanwhile, the nonfluorescent o-phenylenediamine (OPD) was catalytically oxidized to 2,3-diaminophenazine (oxOPD) by CoOOH nanosheets with emission at 572 nm. The acetylcholine (ATCh) was catalytically hydrolyzed by AChE to enzymatic thiocholine (TCh), which decomposed CoOOH to Co2+, recovered the fluorescence of SiQDs and reduced the emission of oxOPD. Fluorescence ratio at F457/F572 serves as signal output for AChE detection within 5 × 10−5–0.05 and 0.05–10 U mL−1, with a limit of detection (LOD) of 3.2 × 10−5 U mL−1. The sensing strategy was applied for AChE assay in human blood and erythrocyte. [Display omitted] •Bifunctional CoOOH nanosheets with peroxidase-like activity and quenching ability.•SiQDs/CoOOH nanosensor is applied for the ratiometric fluorescence detection of AChE.•The enzymatic thiocholine (TCh) can decompose the CoOOH nanosheets to Co2+ through redox reactions.•The sensing strategy was applied for AChE assay in human blood and erythrocyte.