Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan.
Anal Chem. 2010 Sep 15;82(18):7804-13. doi: 10.1021/ac101799f.
Fluorinated compounds exhibit hydrophobic, nonstick, and self-cleaning properties, making them attractive for use as the coating material for biochips. In this study, we copolymerized the fluorinated compound 1H,1H,2H-perfluoro-1-decene (FD) with acrylic acid (AA) and bonded the resulting copolymer with protein G on the surface of polyelectrolyte coated polydimethylsiloxane (PDMS) to form a functional surface that captures antibodies. We demonstrated that the modified PDMS surface remained hydrophobic while becoming resistant to nonspecific protein binding. Thus, aqueous sample solutions formed the droplets (4 μL) on the surface without spreading and drying during the sample printing. Contact angle measurements showed that this functionalized surface was as hydrophobic as the native PDMS with a virtually constant contact angle over seven days of the study under dried condition at 4 °C. Spectroscopic measurements revealed that FD/AA copolymerization formed a homogeneous and highly dense multilayer (50 mg/mm(2)) with a fluorine coverage of 35.4%. Moreover, protein G was shown to covalently bind to AA molecules on the surface at a binding density of 0.24 μg/mm(2). We demonstrated that the fluorinated coating withstood nonspecific binding with extremely low background emission, leading to bioassays that, without the need of blocking agents, exhibited six times more sensitivity than PEG coatings. The fluorinated PDMS antibody microarrays were further applied to accurately determine the absolute concentration of ERα in MCF-7 cells. In conclusion, the unique properties of fluorinated compounds, such as withstanding wetting, nonspecific binding and contamination, make them an excellent coating material for use in sensitive and simple on-chip assays.
含氟化合物具有疏水性、不粘性和自清洁性，因此它们作为生物芯片的涂层材料很有吸引力。在这项研究中，我们将含氟化合物 1H,1H,2H-全氟-1-癸烯（FD）与丙烯酸（AA）共聚，并将所得共聚物键合到聚电解质涂覆的聚二甲基硅氧烷（PDMS）表面的蛋白 G 上，形成一个功能表面，用于捕获抗体。我们证明，改性后的 PDMS 表面保持疏水性的同时，还能抵抗非特异性蛋白质结合。因此，在样品打印过程中，水性样品溶液在表面上形成液滴（4 μL）而不会扩散和干燥。接触角测量表明，这种功能化表面与天然 PDMS 一样疏水，在 4°C 干燥条件下，在研究的七天内，接触角几乎保持不变。光谱测量表明，FD/AA 共聚形成了均匀且高度致密的多层（50 mg/mm(2)），氟覆盖率为 35.4%。此外，蛋白 G 被证明可以共价结合到表面上的 AA 分子上，结合密度为 0.24 μg/mm(2)。我们证明，氟化涂层可以抵抗非特异性结合，具有极低的背景发射，从而使生物测定法无需使用封闭剂，其灵敏度比 PEG 涂层高 6 倍。氟化 PDMS 抗体微阵列进一步用于准确测定 MCF-7 细胞中 ERα 的绝对浓度。总之，含氟化合物的独特性质，如耐润湿、非特异性结合和污染，使它们成为用于敏感和简单的芯片上测定法的优异涂层材料。
