Department of Electronic Engineering, National Chin-Yi University of Technology, Taichung 411030, Taiwan.
Biosensors (Basel). 2022 Feb 12;12(2):115. doi: 10.3390/bios12020115.
Silicon nanowire field effect transistor (NWFET) sensors have been demonstrated to have high sensitivity, are label free, and offer specific detection. This study explored the effect of nanowire dimensions on sensors' sensitivity. We used sidewall spacer etching to fabricate polycrystalline silicon NWFET sensors. This method does not require expensive nanoscale exposure systems and reduces fabrication costs. We designed transistor sensors with nanowires of various lengths and numbers. Hepatitis B surface antigen (HBsAg) was used as the sensing target to explore the relationships of nanowire length and number with biomolecule detection. The experimental results revealed that the sensor with a 3 µm nanowire exhibited high sensitivity in detecting low concentrations of HBsAg. However, the sensor reached saturation when the biomolecule concentration exceeded 800 fg/mL. Sensors with 1.6 and 5 µm nanowires exhibited favorable linear sensing ranges at concentrations from 800 ag/mL to 800 pg/mL. The results regarding the number of nanowires revealed that the use of few nanowires in transistor sensors increases sensitivity. The results demonstrate the effects of nanowire dimensions on the silicon NWFET biosensors.
硅纳米线场效应晶体管（NWFET）传感器具有灵敏度高、无需标记和特异性检测等优点。本研究探讨了纳米线尺寸对传感器灵敏度的影响。我们使用侧壁间隔物刻蚀来制造多晶硅 NWFET 传感器。这种方法不需要昂贵的纳米级曝光系统，降低了制造成本。我们设计了具有不同长度和数量纳米线的晶体管传感器。乙肝表面抗原（HBsAg）被用作传感靶标，以探索纳米线长度和数量与生物分子检测的关系。实验结果表明，3µm 纳米线的传感器在检测低浓度 HBsAg 时具有高灵敏度。然而，当生物分子浓度超过 800 fg/mL 时，传感器达到饱和。具有 1.6 和 5µm 纳米线的传感器在 800 ag/mL 至 800 pg/mL 的浓度范围内表现出良好的线性传感范围。关于纳米线数量的结果表明，在晶体管传感器中使用少量纳米线可以提高灵敏度。结果表明纳米线尺寸对硅 NWFET 生物传感器的影响。
