Single-step imprinting of femtoliter microwell arrays allows digital bioassays with attomolar limit of detection
2017 (English)In: ACS Applied Materials & InterfacesArticle in journal (Refereed) Published
Bead-based microwell array technology is growing as an ultrasensitive target detection tool. However, dissemination of the technology and its commercial use are hampered by current fabrication methods for hydrophilic-in-hydrophobic microwell arrays, which are either expensive or labour-intensive to manufacture, or which results in low bead seeding efficiencies. In this paper, we present a novel single-step manufacturing method for imprinting cheap and disposable hydrophilic-in-hydrophobic microwell arrays suitable for single-molecule detection. Single-step imprinting of hydrophilic-in-hydrophobic microwell arrays is made possible using an innovative surface energy replication approach by means of a hydrophobic thiol-ene polymer formulation. In this polymer, hydrophobic-moiety-containing monomers self-assemble against the hydrophobic surface of the imprinting stamp, which results in a hydrophobic replica surface after polymerization. After removing the stamp, hydrophilic wells are obtained with the well bottoms consisting of glass substrate. We demonstrate that the hydrophilic-in-hydrophobic imprinted microwell arrays enable successful and efficient self-assembly of individual water droplets and seeding of magnetic beads with loading efficiencies up to 96%. We also demonstrate the suitability of the microwell arrays for the isolation and detection of single-molecules achieving a limit of detection of 17.4 aM when performing a streptavidin-biotin binding assay. The ease of manufacturing demonstrated here is expected to allow translation of digital microwell array technology towards diagnostic applications.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017.
digital bioassays, limit of detection, hydrophilic-in-hydrophobic, polymer, OSTE+, OSTEMER
IdentifiersURN: urn:nbn:se:kth:diva-202934DOI: 10.1021/acsami.6b15415OAI: oai:DiVA.org:kth-202934DiVA: diva2:1079112