Silicon nitride (SiN_x) based biosensors have the potential to converge on the technological achievements of semiconductor microfabrication and biotechnology. Development of biofunctionalized SiN_x surface and its integration with other devices will allow us to integrate the biosensing capability with probe control, data acquisition and data processing. Here we use the hydrogen plasma generated by inductively coupled plasma-reactive ion etching (ICP-RIE) technique to produce amino-functionality on the surface of SiN_x which can then be readily used for biomolecule immobilization. ICP-RIE produces high-density hydrogen ions/radicals at low energy, which produces high-density amino group on the SiN_x surface within a short duration of time and with minimal surface damage. In this work, we have demonstrated selective amination of SiN_x surface as compared to Si surface. The as-activated SiN_x surface can be readily biofunctionalized with both protein and oligonucleotide through covalent immobilization. N-5-azido-2-nitrobenzoyloxysuccinimide, a photoactivable amino reactive bifunctional crosslinker, was used and greater than 90% surface coverage was achieved for protein immobilization. In addition, ssDNA immobilization and hybridization with its complemented strand was shown. Thus, we demonstrate a uniform, reliable, fast and economical technique for creating biofunctionalized SiN_x surface that can be used for developing compact high-sensitivity biosensors.

基于氮化硅（SiN _x）的生物传感器具有融合半导体微细加工和生物技术的技术成就的潜力。生物功能化的SiN _x表面的开发及其与其他设备的集成将使我们能够将生物传感功能与探头控制，数据采集和数据处理相集成。在这里，我们使用通过电感耦合等离子体反应离子刻蚀（ICP-RIE）技术生成的氢等离子体在SiN _x的表面上产生氨基官能团，然后可以将其轻松用于生物分子固定化。ICP-RIE以低能量产生高密度氢离子/自由基，从而在SiN _x上产生高密度氨基在很短的时间内保持表面平整，表面损伤最小。在这项工作中，我们证明了与Si表面相比，SiN _x表面的选择性胺化。通过共价固定，可以很容易地用蛋白质和寡核苷酸对活化后的SiN _x表面进行生物功能化。使用N-5-叠氮基-2-硝基苯甲酰氧基琥珀酰亚胺（一种可光活化的氨基反应性双官能交联剂），实现了大于90％的表面固定化蛋白。另外，显示了ssDNA的固定和与其互补链的杂交。因此，我们展示了一种用于创建生物功能化SiN _x表面的统一，可靠，快速且经济的技术，该技术可用于开发紧凑型高灵敏度生物传感器。