title: Patterned Poly(acrylic acid) Brushes Containing Gold Nanoparticles for Peptide Detection by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry.
abstract: Patterned poly(acrylic acid) (PAA) brushes was successfully generated via photolithography and surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid as verified by water contact angle measurements and FT-IR analysis. The carboxyl groups of PAA brushes can act as reducing moieties for in situ synthesis of gold nanoparticles (AuNPs), without the use of additional reducing agent. The formation of AuNPs was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. The glass surface-modified by PAA brushes and immobilized with AuNPs (AuNPs-PAA) can be used as a substrate for SALDI-MS analysis, which is capable of detecting both small peptides having m/z ≤ 600 (glutathione) and large peptides having m/z ≥ 1000 (bradykinin, ICNKQDCPILE) without the interference from matrix signal suggesting that AuNPs were stably trapped within the PAA brushes and the carboxyl groups of PAA can serve as internal proton source. By employing AuNPs as the capture probe, the AuNPs-PAA substrate can selectively identify thiol-containing peptides from the peptide mixtures with LOD as low as 0.1 and 0.05 nM for glutathione and ICNKQDCPILE, respectively. An ability to selectively detect ICNKQDCPILE in a diluted human serum is also demonstrated. The patterned format together with its high sensitivity and selectivity render this newly developed substrate a potential platform for high-throughput analysis of other biomarkers, especially those with low molecular weight in complex biological samples.
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Arunee
authors.initials: A
authors.lastname: Sangsuwan
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Benjaporn
authors.initials: B
authors.lastname: Narupai
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Pornpen
authors.initials: P
authors.lastname: Sae-ung
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Sasithon
authors.initials: S
authors.lastname: Rodtamai
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Nadnudda
authors.initials: N
authors.lastname: Rodthongkum
authors.affiliation: Program in Petrochemistry and Polymer Science, Faculty of Science, ‡Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, §Program in Macromolecular Science, Faculty of Science, and ∥Metallurgy and Materials Science Research Institute, Chulalongkorn University , Phayathai Road, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Voravee P
authors.initials: VP
authors.lastname: Hoven
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000179:Acrylates; D010455:Peptides; D011108:Polymers; D006046:Gold; C036658:acrylic acid