Design and Synthesis of Diverse Functional Kinked Nanowire Structures for Nanoelectronic Bioprobes

Nano Letters (Impact Factor: 12.94). 12/2012; 13(2). DOI: 10.1021/nl304435z
Source: PubMed

ABSTRACT Functional kinked nanowires (KNWs) represent a new class of nanowire building blocks, in which functional devices, for example, nanoscale field-effect transistors (nanoFETs), are encoded in geometrically controlled nanowire superstructures during synthesis. The bottom-up control of both structure and function of KNWs enables construction of spatially isolated point-like nanoelectronic probes that are especially useful for monitoring biological systems where finely tuned feature size and structure are highly desired. Here we present three new types of functional KNWs including (1) the zero-degree KNW structures with two parallel heavily-doped arms of U-shaped structures with a nanoFET at the tip of the "U", (2) series multiplexed functional KNW integrating multi-nanoFETs along the arm and at the tips of V-shaped structures, and (3) parallel multiplexed KNWs integrating nanoFETs at the two tips of W-shaped structures. First, U-shaped KNWs were synthesized with separations as small as 650 nm between the parallel arms, and used to fabricate three-dimensional nanoFET probes at least 3 times smaller than previous V-shaped designs. In addition, multiple nanoFETs were encoded during synthesis in one of arms/tip of V-shaped and distinct arms/tips of W-shaped KNWs. These new multiplexed KNW structures were structurally-verified by optical and electron microscopy of dopant-selective etched samples, and electrically-characterized using scanning gate microscopy and transport measurements. The facile design and bottom-up synthesis of these diverse functional KNWs provides a growing toolbox of building blocks for fabricating highly compact and multiplexed three-dimensional nanoprobes for applications in life sciences, including intra-cellular and deep tissue/cell recordings.

  • [Show abstract] [Hide abstract]
    ABSTRACT: In this article, electrodeposition method is used to demonstrate growth of InSb nanowire (NW) arrays with hierarchical branched structures and complex morphology at room temperature using an all-solution, catalyst-free technique. A gold coated, porous anodic alumina membrane provided the template for the branched NWs. The NWs have a hierarchical branched structure, with three nominal regions: a “trunk” (average diameter of 150 nm), large branches (average diameter of 100 nm), and small branches (average diameter of sub-10 nm to sub-20 nm). The structural properties of the branched NWs were studied using scanning transmission electron microscopy, transmission electron microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and Raman spectroscopy. In the as-grown state, the small branches of InSb NWs were crystalline, but the trunk regions were mostly nanocrystalline with an amorphous boundary. Post-annealing of NWs at 420 °C in argon produced single crystalline structures along ⟨311⟩ directions for the branches and along ⟨111⟩ for the trunks. Based on the high crystallinity and tailored structure in this branched NW array, the effective refractive index allows us to achieve excellent antireflection properties signifying its technological usefulness for photon management and energy harvesting.
    Journal of Applied Physics 08/2014; 116(8):083506-083506-11. DOI:10.1063/1.4893704 · 2.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cancerous transformation may be dependent on correlation between electrical disruptions in the cell membrane and mechanical disruptions of cytoskeleton structures. Silicon nanotube (SiNT)-based electrical probes, as ultra-accurate signal recorders with subcellular resolution, may create many opportunities for fundamental biological research and biomedical applications. Here, we used this technology to electrically monitor cellular mechanosensing. The SiNT probe was combined with an electrically activated glass micropipette aspiration system to achieve a new cancer diagnostic technique that is based on real-time correlation between mechanical and electrical behaviour of single cells. Our studies demonstrated marked changes in the electrical response following increases in the mechanical aspiration force in healthy cells. In contrast, such responses were extremely weak for malignant cells. Confocal microscopy results showed the impact of actin microfilament remodelling on the reduction of the electrical response for aspirated cancer cells due to the significant role of actin in modulating the ion channel activity in the cell membrane.
    Nanoscale 12/2014; 7(5). DOI:10.1039/c4nr06102k · 6.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This review describes work presented in the 2014 inaugural Tsinghua University Press-Springer Nano Research Award lecture, as well as current and future opportunities for nanoscience research at the interface with brain science. First, we briefly summarize some of the considerations and the research journey that has led to our focus on bottom-up nanoscale science and technology. Second, we recapitulate the motivation for and our seminal contributions to nanowirebased nanoscience and technology, including the rational design and synthesis of increasingly complex nanowire structures, and the corresponding broad range of “applications” enabled by the capability to control structure, composition and size from the atomic level upwards. Third, we describe in more detail nanowire-based electronic devices as revolutionary tools for brain science, including (i) motivation for nanoelectronics in brain science, (ii) demonstration of nanowire nanoelectronic arrays for high-spatial/high-temporal resolution extracellular recording, (iii) the development of fundamentally-new intracellular nanoelectronic devices that approach the sizes of single ion channels, (iv) the introduction and demonstration of a new paradigm for innervating cell networks with addressable nanoelectronic arrays in three-dimensions. Last, we conclude with a brief discussion of the exciting and potentially transformative advances expected to come from work at the nanoelectronics-brain interface.
    Nano Research 01/2015; DOI:10.1007/s12274-014-0692-8 · 6.96 Impact Factor