title: Nanopatterned submicron pores as a shield for nonspecific binding in surface plasmon resonance-based sensing.
abstract: We present a novel approach to tackle the most common drawback of using surface plasmon resonance for analyte screening in complex biological matrices--the nonspecific binding to the sensor chip surface. By using a perforated membrane supported by a polymeric gel structure at the evanescent wave penetration depth, we have fabricated a non-fouling sieve above the sensing region. The sieve shields the evanescent wave from nonspecific interactions which interfere with SPR sensing by minimizing the fouled area of the polymeric gel and preventing the translocation of large particles, e.g. micelles or aggregates. The nanopatterned macropores were fabricated by means of colloidal lithography and plasma enhanced chemical vapor deposition of a polyethylene oxide-like film on top of a polymeric gel matrix commonly used in surface plasmon resonance analysis. The sieve was characterized using surface plasmon resonance imaging, contact angle, atomic force microscopy and scanning electron microscopy. The performance of the sieve was studied using an immunoassay for detection of antibiotic residues in full fat milk and porcine serum. The non-fouling membrane presented pores in the 92-138 nm range organized in a hexagonal crystal lattice with a clearance of about 5% of the total surface. Functionally, the membrane with the nanopatterned macropores showed significant improvements in immunoassay robustness and sensitivity in untreated complex samples. The utilization of the sensor built-in sieve for measurements in complex matrices offers reduction in pre-analytical sample preparation steps and thus shortens the total analysis time.
authors.affiliation: RIKILT, Wageningen University and Research centre, P.O. Box 230, 6708 WB Wageningen, The Netherlands. sabina.rebe@wur.nl
authors.forename: Sabina Rebe
authors.initials: SR
authors.lastname: Raz
authors.forename: Gerardo R
authors.initials: GR
authors.lastname: Marchesini
authors.forename: Maria G E G
authors.initials: MG
authors.lastname: Bremer
authors.forename: Pascal
authors.initials: P
authors.lastname: Colpo
authors.forename: Cesar Pascual
authors.initials: CP
authors.lastname: Garcia
authors.forename: Guido
authors.initials: G
authors.lastname: Guidetti
authors.forename: Willem
authors.initials: W
authors.lastname: Norde
authors.forename: Francois
authors.initials: F
authors.lastname: Rossi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000097:blood; D000906:Antibodies / Q000276:immunology; D015374:Biosensing Techniques; D002417:Cattle; D003911:Dextrans / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D007118:Immunoassay; D008892:Milk / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D000906:Antibodies; D003911:Dextrans; D005782:Gels; D011092:Polyethylene Glycols; D006046:Gold