Kamra Tripta, Xu Changgang, Montelius Lars, Schnadt Joachim, Wijesundera Samurdhi A, Yan Mingdi, Ye Lei
Division of Pure and Applied Biochemistry, Lund University , Box 124, 221 00 Lund, Sweden.
Division of Synchrotron Radiation Research, Lund University , Box 118, 221 00 Lund Sweden.
ACS Appl Mater Interfaces. 2015 Dec 16;7(49):27479-85. doi: 10.1021/acsami.5b09500. Epub 2015 Dec 2.
We report a simple and versatile method to covalently immobilize molecularly imprinted polymer (MIP) nanoparticles on a Raman active substrate (Klarite) using a disulfide-derivatized perfluorophenylazide (PFPA-disulfide). Gold-coated Klarite was functionalized with PFPA-disulfide via a gold-sulfur bond. Upon light radiation, the available azido groups were converted to highly reactive singlet perfluorophenyl nitrene that undergoes a CH insertion reaction and form covalent bonds with the MIP nanoparticles. The resulting surfaces were characterized using scanning electron microscopy and surface enhanced Raman spectroscopy to study the morphology and template affinity of the surfaces, respectively. The Raman measurements clearly show a dose-responsive signal when propranolol binds to the MIP surface. Because the MIP particles were covalently attached to the Raman active substrate, the sensing surface was stable and could be reused after regeneration in acetic acid solution. The MIP-based Raman sensor was used successfully to detect propranolol in urine samples (7.7 × 10(-4) M). Our results show that the high selectivity of MIPs and the fingerprint Raman identification can be integrated into a compact sensing unit using high-efficiency photoconjugation. Thus, the method proposed is reliable, efficient and fast for fabricating label-free chemical sensors.
我们报道了一种简单且通用的方法，该方法使用二硫键衍生化的全氟苯基叠氮化物（PFPA-二硫化物）将分子印迹聚合物（MIP）纳米颗粒共价固定在拉曼活性基底（Klarite）上。通过金-硫键，用PFPA-二硫化物对涂金的Klarite进行功能化。在光辐射下，可用的叠氮基团转化为高反应活性的单线态全氟苯基氮烯，其发生CH插入反应并与MIP纳米颗粒形成共价键。使用扫描电子显微镜和表面增强拉曼光谱对所得表面进行表征，分别研究表面的形态和模板亲和力。当普萘洛尔与MIP表面结合时，拉曼测量清楚地显示出剂量响应信号。由于MIP颗粒共价连接到拉曼活性基底上，传感表面稳定，并且在乙酸溶液中再生后可以重复使用。基于MIP的拉曼传感器成功用于检测尿液样本中的普萘洛尔（7.7×10(-4) M）。我们的结果表明，MIP的高选择性和指纹拉曼识别可以通过高效光共轭整合到一个紧凑的传感单元中。因此，所提出的方法对于制造无标记化学传感器是可靠、高效且快速的。
