MAO-B-triggered reaction for an optical triple-signal assay and AND logic gate application based on PEI-functionalized silver nanoparticles.

A novel analytical method was designed and developed that exhibited ultraviolet-visible (UV-Vis), fluorescence (FL), and resonance Rayleigh scattering (RRS) signals for straightforward and comprehensive determination of monoamine oxidase B (MAO-B) using polyethylenimine-functionalized silver nanoparticles (PEI-Ag NPs). Through a facile one-step experiment, and NaOH assisted, in an aqueous solution of 100 ℃ for 40 min PEI reacted with AgNO ₃ to generate PEI-Ag NPs with a yellow color and weak blue fluorescence. Interestingly, phenylacetaldehyde (PAA), a specific product of MAO-B, causes significant enhancement of the three optical signals of UV-Vis, FL, and RRS. A triple-signal readout sensing system was designed and constructed for MAO-B concentration assay. The limit of detection (LOD) was 0.42 (UV-Vis), 3.49 (FL), and 1.97 (RRS) μg/mL. AND logic gate analysis was applied to enhance its accurate identification. Eventually, the feasibility of the method was assessed by measuring MAO-B amount in human serum samples with satisfying recoveries. The method provided a new concept for the clinical detection of MAO-B.
Competing Interests: Declarations. Ethical approval: This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of School of Basic Medicine, Lanzhou University (LZUjcyxy20240330). All participants provided the informed consent before the start of the experiment. Competing interests: The authors declare no competing interests.
(© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)