title: Label-free detection of Staphylococcus aureus captured on immutable ligand arrays.
abstract: The rapid capture and label-free detection of Staphylococcus aureus , an opportunistic bacterium that can infect upon contact, can be performed using periodic microarrays of ligand-protein conjugates created by noncontact (inkjet) printing, darkfield imaging conditions, and a FFT-based readout method. Ink solutes were prepared using bovine serum albumin (BSA) conjugated to a glycan with high affinity for bacterial adhesins and printed as dot-matrix arrays with periodicities of 80-120 μm using a thermal injection method. Upon exposing the glycan-BSA microarrays to live strains of S. aureus , patterns emerge that can be detected under optical darkfield conditions. These patterns can be decoded by fast Fourier transform (FFT) analysis to generate fault-tolerant readout signals that correspond to the capture of S. aureus, with a limit of detection between 10(2) and 10(3) cfu/mL. Inkjet printing provides independent control over array periodicity, enabling FFT signals to be assigned to specific frequencies in reciprocal k-space.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
authors.forename: Avijit K
authors.initials: AK
authors.lastname: Adak
authors.forename: J William
authors.initials: JW
authors.lastname: Boley
authors.forename: David P
authors.initials: DP
authors.lastname: Lyvers
authors.forename: George T
authors.initials: GT
authors.lastname: Chiu
authors.forename: Philip S
authors.initials: PS
authors.lastname: Low
authors.forename: Ronald
authors.initials: R
authors.lastname: Reifenberger
authors.forename: Alexander
authors.initials: A
authors.lastname: Wei
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry; D006801:Humans; D008024:Ligands; D040081:Protein Array Analysis / Q000295:instrumentation / Q000379:methods*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D018829:Adhesins, Bacterial; D008024:Ligands