PubMed: Picomolar-Level Sensing of Cannabidiol by Metal Nanoparticles Functionalized with Chemically Induced Dimerization Binders

PubMed: Picomolar-Level Sensing of Cannabidiol by Metal Nanoparticles Functionalized with Chemically Induced Dimerization Binders

bioRxiv. 2023 Sep 17:2023.09.13.557660. doi: 10.1101/2023.09.13.557660. Preprint.

ABSTRACT

Simple and fast detection of small molecules is critical to health and environmental monitoring. Methods for chemical detection often use mass spectrometers or enzymes; the former relies on expensive equipment and the latter is limited to those that can act as enzyme substrates. Affinity reagents like antibodies can target a variety of small-molecule analytes, but the detection requires successful design of chemically conjugated targets or analogs for competitive binding assays. Here, we developed a generalizable method for highly sensitive and specific in-solution detection of small molecules, using cannabidiol (CBD) as an example. Our sensing platform uses gold nanoparticles (AuNPs) functionalized with a pair of chemically induced dimerization (CID) nanobody binders (nano-binders), where CID triggers AuNPs aggregation and sedimentation in the presence of CBD. Despite moderate binding affinities of the two nano-binders to CBD ( K D s of ∼6 and ∼56 µM), a scheme consisting of CBD-AuNP pre-analytical incubation, centrifugation, and electronic detection (ICED) was devised to demonstrate a high sensitivity (limit of detection of ∼100 picomolar) in urine and saliva, a relatively short assay time (∼2 hours), a large dynamic range (5 logs), and a sufficiently high specificity to differentiate CBD from its analog, tetrahydrocannabinol. The high sensing performance was achieved with the multivalency of AuNP sensing, the ICED scheme that increases analyte concentrations in a small assay volume, and a portable electronic detector. This sensing system is readily coupled to other binders for wide molecular diagnostic applications.

PMID:37745324 | PMC:PMC10515952 | DOI:10.1101/2023.09.13.557660

https://pubmed.ncbi.nlm.nih.gov/37745324/?utm_source=Chrome&utm_medium=rss&utm_campaign=pubmed-2&utm_content=1NqsX9BbHlDygQ8TcgAlJilHgPpiuKQtyIr–a3-xbLzPoB9xM&fc=20220928170152&ff=20230925190615&v=2.17.9.post6+86293ac September 25, 2023 10:00 am