School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA.
Nat Commun. 2011 Dec 6;2:578. doi: 10.1038/ncomms1587.
The challenge for new biosensors is to achieve detection of biomolecules at low concentrations, which is useful for early-stage disease detection. Nanomechanical biosensors are promising in medical diagnostic applications. For nanomechanical biosensing at low concentrations, a sufficient resonator device surface area is necessary for molecules to bind to. Here we present a low-concentration (500 aM sensitivity) DNA sensor, which uses a novel nanomechanical resonator with ordered vertical nanowire arrays on top of a Si/SiO(2) bilayer thin membrane. The high sensitivity is achieved by the strongly enhanced total surface area-to-volume ratio of the resonator (10(8) m(-1)) and the state-of-the-art mass-per-area resolution (1.8×10(-12) kg m(-2)). Moreover, the nanowire array forms a photonic crystal that shows strong light trapping and absorption over broad-band optical wavelengths, enabling high-efficiency broad-band opto-thermo-mechanical remote device actuation and biosensing on a chip. This method represents a mass-based platform technology that can sense molecules at low concentrations.
新型生物传感器面临的挑战是实现对低浓度生物分子的检测，这对于早期疾病检测非常有用。纳米机械生物传感器在医学诊断应用中具有广阔的应用前景。对于低浓度的纳米机械生物传感，需要有足够的谐振器装置表面积来使分子结合。在这里，我们提出了一种低浓度（500 aM 灵敏度）DNA 传感器，它使用了一种新型纳米机械谐振器，其顶部有有序的垂直纳米线阵列，位于 Si/SiO2 双层薄膜上。通过强烈增强谐振器的总表面积与体积比（108 m-1）和最先进的质量与面积分辨率（1.8×10-12 kg m-2），实现了高灵敏度。此外，纳米线阵列形成了光子晶体，在宽波段光学波长下表现出强烈的光捕获和吸收，从而能够在芯片上实现高效的宽波段光热机械远程器件致动和生物传感。该方法代表了一种基于质量的平台技术，可用于检测低浓度的分子。
