Biomolecular Sensing and Diagnostics, Food and Biobased Research, Wageningen University and Research Centre, Bornse Weilanden 9, 6708 AA Wageningen, The Netherlands.
Analyst. 2013 Jan 21;138(2):518-24. doi: 10.1039/c2an36104c.
Non-contact inkjet printing technology is one of the most promising tools for producing microarrays. The quality of the microarray depends on the type of the substrate used for printing biomolecules. Various porous and non-porous substrates have been used in the past, but due to low production cost and easy availability, non-porous substrates like glass and plastic are preferred over porous substrates. On these non-porous substrates, obtaining spot uniformity and a high signal to noise ratio is a big challenge. In our research work, we have modified pristine glass slides using various silanes to produce a range of hydrophobic glass substrates. The hydrophobicities of the slides expressed in the contact angle (θ) of a sessile drop of water were 49°, 61°, 75°, 88° and 103°. Using a non-contact inkjet printer, microarrays of biotinylated biomolecules (BSA and IgG) were produced on these modified glass substrates, pristine (untreated) glass and also on HTA polystyrene slides. The uniformity of the spots, reflecting the distribution of the biomolecules in the spots, was analyzed and compared using confocal laser scanning microscopy (CLSM). The quality of the spots was superior on the glass slide with a contact angle of ∼75°. We also investigated the influence of the hydrophobicity of the substrate on a two-step, real diagnostic antibody assay. This nucleic acid microarray immunoassay (NAMIA) for the detection of Staphylococcus aureus showed that on highly hydrophilic (θ < 10°) and hydrophobic substrates (θ > 100°) the assay signal was low, whereas an excellent signal was obtained on the substrates with intermediate contact angles, θ ∼ 61° and θ ∼ 75°, respectively.
非接触喷墨打印技术是非微阵列制作最有前途的工具之一。微阵列的质量取决于用于打印生物分子的基片类型。过去曾使用过各种多孔和非多孔基片，但由于生产成本低且易于获得，因此非多孔基片（如玻璃和塑料）比多孔基片更受欢迎。在这些非多孔基片上，获得斑点均匀性和高信噪比是一个巨大的挑战。在我们的研究工作中，我们使用各种硅烷对原始玻璃载玻片进行了修饰，以产生一系列疏水性玻璃基片。通过水的固着液滴接触角（θ）来表示基片的疏水性，分别为 49°、61°、75°、88°和 103°。使用非接触式喷墨打印机，在这些修饰的玻璃基片、原始（未经处理）玻璃和 HTA 聚苯乙烯载玻片上生成了生物素化生物分子（BSA 和 IgG）的微阵列。使用共焦激光扫描显微镜（CLSM）分析和比较了斑点的均匀性，斑点的均匀性反映了斑点中生物分子的分布。在接触角约为 75°的玻璃载玻片上，斑点的质量最佳。我们还研究了基片疏水性对两步实际诊断抗体检测的影响。这种用于检测金黄色葡萄球菌的核酸微阵列免疫分析（NAMIA）表明，在高亲水性（θ < 10°）和疏水性基片（θ > 100°）上，检测信号较低，而在中间接触角θ分别约为 61°和 75°的基片上，获得了优异的信号。
