Professional Education


  • Ph.D., Harvard University, Chemistry (2020)
  • M.A., Harvard University, Chemistry (2017)
  • B.S., Fudan University, Materials Science (2014)

Stanford Advisors


All Publications


  • Nanowire-enabled bioelectronics NANO TODAY Zhang, A., Lee, J., Lieber, C. M. 2021; 38
  • Nanowire probes could drive high-resolution brain-machine interfaces NANO TODAY Zhang, A., Zhao, Y., You, S., Lieber, C. M. 2020; 31
  • Scalable ultrasmall three-dimensional nanowire transistor probes for intracellular recording NATURE NANOTECHNOLOGY Zhao, Y., You, S., Zhang, A., Lee, J., Huang, J., Lieber, C. M. 2019; 14 (8): 783-+

    Abstract

    New tools for intracellular electrophysiology that push the limits of spatiotemporal resolution while reducing invasiveness could provide a deeper understanding of electrogenic cells and their networks in tissues, and push progress towards human-machine interfaces. Although significant advances have been made in developing nanodevices for intracellular probes, current approaches exhibit a trade-off between device scalability and recording amplitude. We address this challenge by combining deterministic shape-controlled nanowire transfer with spatially defined semiconductor-to-metal transformation to realize scalable nanowire field-effect transistor probe arrays with controllable tip geometry and sensor size, which enable recording of up to 100 mV intracellular action potentials from primary neurons. Systematic studies on neurons and cardiomyocytes show that controlling device curvature and sensor size is critical for achieving high-amplitude intracellular recordings. In addition, this device design allows for multiplexed recording from single cells and cell networks and could enable future investigations of dynamics in the brain and other tissues.

    View details for DOI 10.1038/s41565-019-0478-y

    View details for Web of Science ID 000478794700018

    View details for PubMedID 31263191

  • Specific detection of biomolecules in physiological solutions using graphene transistor biosensors PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Gao, N., Gao, T., Yang, X., Dai, X., Zhou, W., Zhang, A., Lieber, C. M. 2016; 113 (51): 14633–38

    Abstract

    Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high-ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high-ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.

    View details for DOI 10.1073/pnas.1625010114

    View details for Web of Science ID 000390044900045

    View details for PubMedID 27930344

    View details for PubMedCentralID PMC5187689

  • Epitaxial Growth of Lattice-Mismatched Core-Shell TiO2@MoS2 for Enhanced Lithium-Ion Storage SMALL Dai, R., Zhang, A., Pan, Z., Al-Enizi, A. M., Elzatahry, A. A., Hu, L., Zheng, G. 2016; 12 (20): 2792-2799

    Abstract

    Core-shell structured nanohybrids are currently of significant interest due to their synergetic properties and enhanced performances. However, the restriction of lattice mismatch remains a severe obstacle for heterogrowth of various core-shells with two distinct crystal structures. Herein, a controlled synthesis of lattice-mismatched core-shell TiO2 @MoS2 nano-onion heterostructures is successfully developed, using unilamellar Ti0.87 O2 nanosheets as the starting material and the subsequent epitaxial growth of MoS2 on TiO2 . The formation of these core-shell nano-onions is attributed to an amorphous layer-induced heterogrowth mechanism. The number of MoS2 layers can be well tuned from few to over ten layers, enabling layer-dependent synergistic effects. The core-shell TiO2 @MoS2 nano-onion heterostructures exhibit significantly enhanced energy storage performance as lithium-ion battery anodes. The approach has also been extended to other lattice-mismatched systems such as TiO2 @MoSe2 , thus suggesting a new strategy for the growth of well-designed lattice-mismatched core-shell structures.

    View details for DOI 10.1002/smll.201600237

    View details for Web of Science ID 000378424400014

    View details for PubMedID 27062267

  • Synthesis, Study, and Discrete Dipole Approximation Simulation of Ag-Au Bimetallic Nanostructures NANOSCALE RESEARCH LETTERS Hu, Y., Zhang, A., Li, H., Qian, D., Chen, M. 2016; 11: 209

    Abstract

    Water-soluble Ag-Au bimetallic nanostructures were prepared via co-reduction and seed-mediated growth routes employing poly-(4-styrenesulfonic acid-co-maleic acid) (PSSMA) as both a reductant and a stabilizer. Ag-Au alloy nanoparticles were obtained by the co-reduction of AgNO3 and HAuCl4, while Ag-Au core-shell nanostructures were prepared through seed-mediated growth using PSSMA-Au nanoparticle seeds in a heated AgNO3 solution. The optical properties of the Ag-Au alloy and core-shell nanostructures were studied, and the growth mechanism of the bimetallic nanoparticles was investigated. Plasmon resonance bands in the range 422 to 517 nm were observed for Ag-Au alloy nanoparticles, while two plasmon resonances were found in the Ag-Au core-shell nanostructures. Furthermore, discrete dipole approximation theoretical simulation was used to assess the optical property differences between the Ag-Au alloy and core-shell nanostructures. Composition and morphology studies confirmed that the synthesized materials were Ag-Au bimetallic nanostructures.

    View details for DOI 10.1186/s11671-016-1435-4

    View details for Web of Science ID 000374678800002

    View details for PubMedID 27094823

    View details for PubMedCentralID PMC4837194

  • Spontaneous Internalization of Cell Penetrating Peptide-Modified Nanowires into Primary Neurons NANO LETTERS Lee, J., Zhang, A., You, S., Lieber, C. M. 2016; 16 (2): 1509-1513

    Abstract

    Semiconductor nanowire (NW) devices that can address intracellular electrophysiological events with high sensitivity and spatial resolution are emerging as key tools in nanobioelectronics. Intracellular delivery of NWs without compromising cellular integrity and metabolic activity has, however, proven difficult without external mechanical forces or electrical pulses. Here, we introduce a biomimetic approach in which a cell penetrating peptide, the trans-activating transcriptional activator (TAT) from human immunodeficiency virus 1, is linked to the surface of Si NWs to facilitate spontaneous internalization of NWs into primary neuronal cells. Confocal microscopy imaging studies at fixed time points demonstrate that TAT-conjugated NWs (TAT-NWs) are fully internalized into mouse hippocampal neurons, and quantitative image analyses reveal an ca. 15% internalization efficiency. In addition, live cell dynamic imaging of NW internalization shows that NW penetration begins within 10-20 min after binding to the membrane and that NWs become fully internalized within 30-40 min. The generality of cell penetrating peptide modification method is further demonstrated by internalization of TAT-NWs into primary dorsal root ganglion (DRG) neurons.

    View details for DOI 10.1021/acs.nanolett.6b00020

    View details for Web of Science ID 000370215200103

    View details for PubMedID 26745653

  • Nano-Bioelectronics CHEMICAL REVIEWS Zhang, A., Lieber, C. M. 2016; 116 (1): 215-257

    Abstract

    Nano-bioelectronics represents a rapidly expanding interdisciplinary field that combines nanomaterials with biology and electronics and, in so doing, offers the potential to overcome existing challenges in bioelectronics. In particular, shrinking electronic transducer dimensions to the nanoscale and making their properties appear more biological can yield significant improvements in the sensitivity and biocompatibility and thereby open up opportunities in fundamental biology and healthcare. This review emphasizes recent advances in nano-bioelectronics enabled with semiconductor nanostructures, including silicon nanowires, carbon nanotubes, and graphene. First, the synthesis and electrical properties of these nanomaterials are discussed in the context of bioelectronics. Second, affinity-based nano-bioelectronic sensors for highly sensitive analysis of biomolecules are reviewed. In these studies, semiconductor nanostructures as transistor-based biosensors are discussed from fundamental device behavior through sensing applications and future challenges. Third, the complex interface between nanoelectronics and living biological systems, from single cells to live animals, is reviewed. This discussion focuses on representative advances in electrophysiology enabled using semiconductor nanostructures and their nanoelectronic devices for cellular measurements through emerging work where arrays of nanoelectronic devices are incorporated within three-dimensional cell networks that define synthetic and natural tissues. Last, some challenges and exciting future opportunities are discussed.

    View details for DOI 10.1021/acs.chemrev.5b00608

    View details for Web of Science ID 000368323200006

    View details for PubMedID 26691648

    View details for PubMedCentralID PMC4867216

  • Nanowires: Building Blocks for Nanoscience and Nanotechnology NANOWIRES: BUILDING BLOCKS FOR NANOSCIENCE AND NANOTECHNOLOGY Zhang, A., Zheng, G., Lieber, C. M. 2016: 1-322
  • Hyaluronan/Tween 80-assisted synthesis of silver nanoparticles for biological application JOURNAL OF NANOPARTICLE RESEARCH Li, H., Zhang, A., Sui, L., Qian, D., Chen, M. 2015; 17 (2)
  • Semiconductor nanowires for biosensors Semiconductor Nanowires: Materials, Synthesis, Characterization and Applications Zhang, A., Zheng, G. Woodhead Publishing. 2015: 471-490
  • Kinetically-controlled template-free synthesis of hollow silica micro-/nanostructures with unusual morphologies NANOTECHNOLOGY Zhang, A., Li, H., Qian, D., Chen, M. 2014; 25 (13): 135608

    Abstract

    We report a kinetically-controlled template-free room-temperature production of hollow silica materials with various novel morphologies, including tubes, crutches, ribbons, bundles and bells. The obtained products, which grew in a well-controlled manner, were monodispersed in shape and size. The role of ammonia, sodium citrate, polyvinylpyrrolidone, chloroauric acid and NaCl in shape control is discussed in detail. The oriented growth of these micro-/nanostructures directed by reverse micelles followed a solution-solution-solid (SSS) mechanism, similar to the classic vapor-liquid-solid mechanism. The evolution processes of silica rods, tubes, crutches, bundles and bells were recorded using transmission electron microscopy to prove the SSS mechanism.

    View details for DOI 10.1088/0957-4484/25/13/135608

    View details for Web of Science ID 000332858700020

    View details for PubMedID 24598146

  • pH-Dependent shape changes of water-soluble CdS nanoparticles JOURNAL OF NANOPARTICLE RESEARCH Zhang, A., Tan, Q., Li, H., Sui, L., Qian, D., Chen, M. 2013; 16 (1)
  • Simulated optical properties of noble metallic nanopolyhedra with different shapes and structures EUROPEAN PHYSICAL JOURNAL D Zhang, A., Qian, D., Chen, M. 2013; 67 (11)
  • Morphology-controllable synthesis of ZnO nano-/microstructures by a solvothermal process in ethanol solution CRYSTAL RESEARCH AND TECHNOLOGY Zhang, A., Zhang, L., Sui, L., Qian, D., Chen, M. 2013; 48 (11): 947-955
  • Reducing Properties of Polymers in the Synthesis of Noble Metal Nanoparticles POLYMER REVIEWS Zhang, A., Cai, L., Sui, L., Qian, D., Chen, M. 2013; 53 (2): 240-276
  • Large-scale synthesis and self-organization of silver nanoparticles with Tween 80 as a reductant and stabilizer NANOSCALE RESEARCH LETTERS Li, H., Zhang, A., Hu, Y., Sui, L., Qian, D., Chen, M. 2012; 7: 612

    Abstract

    Tween 80 (polysorbate 80) has been used as a reducing agent and protecting agent to prepare stable water-soluble silver nanoparticles on a large scale through a one-pot process, which is simple and environmentally friendly. Silver ions can accelerate the oxidation of Tween 80 and then get reduced in the reaction process. The well-ordered arrays such as ribbon-like silver nanostructures could be obtained by adjusting the reaction conditions. High-resolution transmission electron microscopy confirms that ribbon-like silver nanostructures (approximately 50 nm in length and approximately 2 μm in width) are composed of a large number of silver nanocrystals with a size range of 2 to 3 nm. In addition, negative absorbance around 320 nm in the UV-visible spectra of silver nanoparticles has been observed, probably owing to the instability of nanosized silver colloids.

    View details for DOI 10.1186/1556-276X-7-612

    View details for Web of Science ID 000209057000001

    View details for PubMedID 23127253

    View details for PubMedCentralID PMC3503618