title: Covalent immobilization of molecularly imprinted polymer nanoparticles on a gold surface using carbodiimide coupling for chemical sensing.
abstract: One challenging task in building (bio)chemical sensors is the efficient and stable immobilization of receptor on a suitable transducer. Herein, we report a method for covalent immobilization of molecularly imprinted core-shell nanoparticles for construction of robust chemical sensors. The imprinted nanoparticles with a core-shell structure have selective molecular binding sites in the core and multiple amino groups in the shell. The model Au transducer surface is first functionalized with a self-assembled monolayer of 11-mercaptoundecanoic acid. The 11-mercaptoundecanoic acid is activated by treatment with carbodiimide/N-hydroxysuccinimide and then reacted with the core-shell nanoparticles to form amide bonds. We have characterized the process by studying the treated surfaces after each preparation step using atomic force microscopy, scanning electron microscopy, fluorescence microscopy, contact angle measurements and X-ray photoelectron spectroscopy. The microscopy results show the successful immobilization of the imprinted nanoparticles on the surface. The photoelectron spectroscopy results further confirm the success of each functionalization step. Further, the amino groups on the MIP surface were activated by electrostatically adsorbing negatively charged Au colloids. The functionalized surface was shown to be active for surface enhanced Raman scattering detection of propranolol. The particle immobilization and surface enhanced Raman scattering approach described here has a general applicability for constructing chemical sensors in different formats.
authors.affiliation: Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden; Division of Pure & Applied Biochemistry, Lund University, Box 124, 221 00 Lund, Sweden.
authors.forename: Tripta
authors.initials: T
authors.lastname: Kamra
authors.affiliation: Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden; Division of Pure & Applied Biochemistry, Lund University, Box 124, 221 00 Lund, Sweden.
authors.forename: Shilpi
authors.initials: S
authors.lastname: Chaudhary
authors.affiliation: Division of Pure & Applied Biochemistry, Lund University, Box 124, 221 00 Lund, Sweden.
authors.forename: Changgang
authors.initials: C
authors.lastname: Xu
authors.affiliation: Division of Solid State Physics, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Montelius
authors.affiliation: Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00 Lund, Sweden.
authors.forename: Joachim
authors.initials: J
authors.lastname: Schnadt
authors.affiliation: Division of Pure & Applied Biochemistry, Lund University, Box 124, 221 00 Lund, Sweden. Electronic address: lei.ye@tbiokem.lth.se.
authors.forename: Lei
authors.initials: L
authors.lastname: Ye
mesh_terms: D000327:Adsorption; D002234:Carbodiimides / Q000737:chemistry*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D054802:Molecular Imprinting; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D002234:Carbodiimides; D011108:Polymers; D006046:Gold
keywords: Carbodiimide; Molecularly imprinted polymer; Nanoparticle; Propranolol; Self-assembled monolayer; Surface enhanced Raman spectroscopy; X-ray photoelectron spectroscopy