title: Solid-phase colorimetric sensor based on gold nanoparticle-loaded polymer brushes: lead detection as a case study.
abstract: We introduce a novel solid-phase colorimetric sensor facilely fabricated by loading unmodified gold nanoparticles into poly(oligo(ethylene glycol)methacrylate) (POEGMA) brushes grown on glass. Our work reports the first synergistic combination of metallic nanoparticles acting as a colorimetric sensing module with a nonfouling polymer matrix acting both as a nonrigid scaffold and a screen to reduce interference from nontarget molecules. In addition, as the nanocomposite is formed on a transparent substrate, solid-phase detection can be performed in the same manner as in the solution-phase. We demonstrate the use of this unique platform for label-free lead detection based on the release of gold nanoparticles from the polymer brush upon exposure to lead ions. An ultralow limit-of-detection of 25 pM (S/N = 3) and a dynamic range of 100 pM to 100 nM (R(2) = 0.987) are achieved. Furthermore, the detection is up to 1000-fold more selective to lead over other common heavy metal ions.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457.
authors.forename: Abdul Rahim
authors.initials: AR
authors.lastname: Ferhan
authors.forename: Longhua
authors.initials: L
authors.lastname: Guo
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.forename: Seungpyo
authors.initials: S
authors.lastname: Hong
authors.forename: Dong-Hwan
authors.initials: DH
authors.lastname: Kim
mesh_terms: D055664:Electrochemical Techniques / Q000379:methods*; D005898:Glass; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007854:Lead / Q000097:blood*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids
chemical_list: D008689:Methacrylates; D011109:Polymethacrylic Acids; C528061:poly(poly(ethylene glycol)methacrylate); D007854:Lead; D011092:Polyethylene Glycols; D006046:Gold