寡核苷酸在聚甲基丙烯酸甲酯/聚N-异丙基丙烯酰胺核壳乳胶上的吸附：通过荧光探测聚N-异丙基丙烯酰胺壳层的极性

Adsorption of oligonucleotides on PMMA/PNIPAM core-shell latexes: polarity of the PNIPAM shell probed by fluorescence.

作者信息

Prazeres T J V, Santos A M, Martinho J M G, Elaïssari A, Pichot C

机构信息

Centro de Química-Física Molecular, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal.

出版信息

Langmuir. 2004 Aug 3;20(16):6834-40. doi: 10.1021/la049609u.

DOI:10.1021/la049609u

PMID:15274592

Abstract

The adsorption of a rhodamine X labeled oligonucleotide composed of 25-mers of thymine (dT(25)-ROX) onto the thermosensitive shell of PMMA/PNIPAM core-shell latex particles was studied at 22 and 40 degrees C, below and above the T(VPT) (volume phase transition temperature) of the PNIPAM shell, respectively. The experimental binding isotherms were well fitted with the cooperative Hill model. The Hill coefficient is lower than 1 at both temperatures showing that the adsorption is anticooperative. The polarity of the shell was probed by both the lifetimes and solvatochromic shifts of the zwitterionic form of rhodamine X. For temperatures below the shell T(VPT) has a polarity similar to that of water, while for temperatures above the transition the polarity is equivalent to that of a water/dioxane mixture with 30% (v/v) water.

摘要

研究了在22℃和40℃下，分别低于和高于聚N-异丙基丙烯酰胺（PNIPAM）壳层的体积相转变温度（T(VPT)）时，由25个胸腺嘧啶组成的若丹明X标记的寡核苷酸（dT(25)-ROX）在聚甲基丙烯酸甲酯/聚N-异丙基丙烯酰胺（PMMA/PNIPAM）核壳乳胶颗粒热敏壳层上的吸附情况。实验结合等温线与协同希尔模型拟合良好。在两个温度下，希尔系数均低于1，表明吸附是反协同的。通过若丹明X两性离子形式的寿命和溶剂化显色位移来探测壳层的极性。对于低于壳层T(VPT)的温度，其极性与水相似，而对于高于转变温度的情况，极性相当于含有30%（v/v）水的水/二氧六环混合物的极性。