Grenier Casey J, Timberman Anthony, Yang Rongfang, Csoros John, Papantones Alex, Deravi Leila F, Seitz W Rudolf
Tekscan, Inc., 307 W. First St., Boston, MA 02127, USA.
Department of Chemistry, University of New Hampshire, Durham NH 03824, USA.
Sensors (Basel). 2018 Apr 25;18(5):1330. doi: 10.3390/s18051330.
A new type of biomimetic templated copolymer has been prepared by reverse addition fragmentation chain transfer polymerization (RAFT) in dioxane. The initial formulation includes the template fluorescein, -isopropylacrylamide (NIPAM, 84 mol %), methacrylic acid (MAA, 5-mol %), 4-vinylpyridine (4-VP, 9 mmol %), and ,′-methylenebis(acrylamide) (MBA, 2 mol %). PolyNIPAM is a thermosensitive polymer that comes out of aqueous solution above its lower critical solution temperature forming hydrophobic ‘crosslinks’. MAA and 4-VP interact in dioxane forming acid⁻base crosslinks. The excess 4-VP serves as a recognition monomer organizing around the template fluorescein to form a binding site that is held in place by the noncovalent and covalent crosslinks. The MBA is a covalent crosslinker. The RAFT agent in the resulting copolylmer was reduced to a thiol and attached to gold nanoparticles. The gold nanoparticle bound copolymer binds fluorescein completely in less than two seconds with an affinity constant greater than 10⁸ M. A reference copolymer prepared with the same monomers by the same procedure binds fluorescein much more weakly.
一种新型的仿生模板共聚物已通过在二氧六环中进行的可逆加成断裂链转移聚合（RAFT）制备而成。初始配方包括模板荧光素、N-异丙基丙烯酰胺（NIPAM，84摩尔%）、甲基丙烯酸（MAA，5摩尔%）、4-乙烯基吡啶（4-VP，9毫摩尔）和N,N'-亚甲基双丙烯酰胺（MBA，2摩尔%）。聚NIPAM是一种热敏聚合物，在其较低临界溶液温度以上会从水溶液中析出，形成疏水的“交联”。MAA和4-VP在二氧六环中相互作用形成酸碱交联。过量的4-VP作为识别单体围绕模板荧光素排列，形成一个由非共价和共价交联固定在位的结合位点。MBA是一种共价交联剂。所得共聚物中的RAFT试剂被还原为硫醇并连接到金纳米颗粒上。金纳米颗粒结合的共聚物在不到两秒的时间内就能完全结合荧光素，其亲和常数大于10⁸ M。通过相同程序用相同单体制备的参比共聚物对荧光素的结合能力则弱得多。
