Valderas-Gutiérrez Julia, Davtyan Rubina, Sivakumar Sudhakar, Anttu Nicklas, Li Yuyu, Flatt Patrick, Shin Jae Yen, Prinz Christelle N, Höök Fredrik, Fioretos Thoas, Magnusson Martin H, Linke Heiner
NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden.
Division of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden.
ACS Appl Nano Mater. 2022 Jul 22;5(7):9063-9071. doi: 10.1021/acsanm.2c01372. Epub 2022 Jul 1.
Sensitive detection of low-abundance biomolecules is central for diagnostic applications. Semiconductor nanowires can be designed to enhance the fluorescence signal from surface-bound molecules, prospectively improving the limit of optical detection. However, to achieve the desired control of physical dimensions and material properties, one currently uses relatively expensive substrates and slow epitaxy techniques. An alternative approach is aerotaxy, a high-throughput and substrate-free production technique for high-quality semiconductor nanowires. Here, we compare the optical sensing performance of custom-grown aerotaxy-produced Ga(As)P nanowires vertically aligned on a polymer substrate to GaP nanowires batch-produced by epitaxy on GaP substrates. We find that signal enhancement by individual aerotaxy nanowires is comparable to that from epitaxy nanowires and present evidence of single-molecule detection. Platforms based on both types of nanowires show substantially higher normalized-to-blank signal intensity than planar glass surfaces, with the epitaxy platforms performing somewhat better, owing to a higher density of nanowires. With further optimization, aerotaxy nanowires thus offer a pathway to scalable, low-cost production of highly sensitive nanowire-based platforms for optical biosensing applications.
低丰度生物分子的灵敏检测对诊断应用至关重要。半导体纳米线可设计用于增强表面结合分子的荧光信号，有望提高光学检测的极限。然而，为了实现对物理尺寸和材料特性的理想控制，目前人们使用的是相对昂贵的衬底和缓慢的外延技术。另一种方法是气相聚合法，这是一种用于高质量半导体纳米线的高通量且无衬底的生产技术。在此，我们将在聚合物衬底上垂直排列的定制生长的气相聚合法制备的Ga(As)P纳米线与通过在GaP衬底上外延批量生产的GaP纳米线的光学传感性能进行了比较。我们发现，单个气相聚合法纳米线的信号增强与外延纳米线相当，并给出了单分子检测的证据。基于这两种纳米线的平台均显示出比平面玻璃表面显著更高的归一化空白信号强度，由于纳米线密度更高，外延平台的表现略好。通过进一步优化，气相聚合法纳米线因此为可扩展、低成本生产用于光学生物传感应用的高灵敏度基于纳米线的平台提供了一条途径。
