title: SPR Biosensing in crude serum using ultralow fouling binary patterned peptide SAM.
abstract: Near-zero fouling monolayers based on binary patterned peptides allow low nanomolar detection of the matrix metalloproteinase-3 (MMP-3) directly in crude bovine serum, without sample pretreatment, secondary antibody detection or signal amplification. The peptide 3-MPA-HHHDD-OH (3-MPA, 3-mercaptopropionic acid) was found optimal compared to other binary patterned peptides based on 3-MPA-A(x)-B(y)-OH, where 0 <or= x, y <or= 5, and x + y = 5, and compared to PEG. In this study, amino acid A was His, Asp, Ser, or Leu, and amino acid B was His, Asp, or Ser. Zwitterionic peptides and other peptides exhibited excellent resistance to nonspecific adsorption. Binary patterned peptides were capped with 3-MPA on the N-terminus providing a monolayer with the C-terminus carboxylic acid available to subsequently immobilize antibodies. Thereby, an IgG biosensor demonstrated the efficiency of binary patterned peptides in SPR biosensing with a detection limit of 1-10 pM in PBS, similar to other optical or electrochemical techniques. This protocol was applied to establish a calibration curve for MMP-3, an analyte of clinical interest for many pathologies and a potential indicator of cancer. The LOD for MMP-3 was 0.14 nM in PBS, with a linearity of up to 50 nM. With the use of PBS calibration, MMP-3 was quantified at low nanomolar in undiluted bovine serum. The SPR response in serum was statistically the same as in PBS. A sensor exposed to blank serum exhibited negligible nonspecific adsorption. Hence, binary patterned peptides are suitable for biosensing directly in complex biological matrixes.
authors.affiliation: Département de Chimie, Université de Montréal, Quebec, Canada, H3C 3J7.
authors.forename: Olivier R
authors.initials: OR
authors.lastname: Bolduc
authors.forename: Joelle N
authors.initials: JN
authors.lastname: Pelletier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Masson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015374:Biosensing Techniques; D001798:Blood Proteins / Q000032:analysis* / Q000737:chemistry; D002417:Cattle; D004800:Enzymes, Immobilized / Q000737:chemistry; D019278:Matrix Metalloproteinase 3 / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D001798:Blood Proteins; D004800:Enzymes, Immobilized; D010455:Peptides; D019278:Matrix Metalloproteinase 3