- 标题
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- 实验方案
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Multisegmented Metallic Nanorods: Sub-10 nm Growth, Nanoscale Manipulation, and Subwavelength Imaging
摘要： Multisegmented metallic nanorods (MS-M-NRs) have attracted increasing attention thanks to their integrated structures and complex functions. The integration of nanoscale segments in 1D enables maximum exposure of each segment and enhanced interaction between adjacent segments. Such structural integration will induce functional complexity in the nanorods, leading to superior properties for the individual components. Herein, recent progress on the development of MS-M-NRs is reviewed. Their precise fabrication, nanoscale manipulation, and subwavelength imaging, as well as simultaneous manipulation and imaging are discussed, respectively. Specifically, precise fabrication of MS-M-NRs focuses on porous anodic alumina (PAA) templated electrodeposition, which enables sub-10 nm growth of the segments and their interfaces/fronts. Nanoscale manipulation of MS-M-NRs introduces the fundamental methods that are employed for delicate movement control on the nanorods through internal or external stimulations. Subwavelength imaging of MS-M-NRs highlights the achievements on identification and location of constituent nanoscale segments/gaps based on their differences and interactions. Simultaneous manipulation and imaging of MS-M-NRs addresses the significance and potential applications of the nanorods with magnetic–plasmonic dual modulation. The development of MS-M-NRs will greatly contribute to materials science and nanoscience/nanotechnology.
关键词： metallic nanorods,porous anodic alumina (PAA),electrodeposition,imaging,manipulation
更新于2025-09-23 15:22:29
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Ultrasensitive and Label-Free Detection of Cell Surface Glycan Using Nanochannel-Ionchannel Hybrid Coupled with Electrochemical Detector
摘要： In this work, asymmetric nanochannel-ionchannel of porous anodic alumina (PAA) coupled with electrochemical detector was used for sensitive and label-free detection of cell surface glycan. The amplified ionic current caused by array nanochannels as well as the ionic current rectification (ICR) caused by asymmetric geometry endows PAA with sensitive ionic current response. Functionalized with the special molecular probe, the constructed nanofluidic device can be used for selective recognition and detection of glycan in real-time and label-free format. In addition, due to the subnanosize of ionchannels, the probe immobilization and glycan recognition is carried out on the outer surface of PAA, avoiding the blockage of PAA nanochannel by samples, which promises the reproducibility and accuracy of the present method toward bioanalysis. Results show that the glycan concentration ranging from 10 fM to 10 nM can be successfully detected with a detection limit of ~10 aM, which is substantially lower than most previous works. The designed strategy provides a valuable platform for sensitive and label-free detection of cell surface glycan, which acts as a promising candidate in pathological research and cancer diagnosis.
关键词： porous anodic alumina,ionic current rectification,cell surface glycan,nanochannel-ionchannel hybrid,nanofluidics
更新于2025-09-23 15:19:57
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On-substrate porous-anodic-alumina-assisted gold nanostructure arrays: Meeting the challenges of various sizes and interfaces
摘要： Arrays of 0- and 1-dimentional noble-metal nanostructures aligned on solid substrates are in demand for nanocatalysis, bio- and optical sensing, or biomolecular analysis. Here we introduce a range of advances based on a systematic research towards the porous-anodic-alumina (PAA)-assisted on- substrate arrays of gold nanostructures, such as rods and spheres, spatially-separated and highly aligned on a metal or semiconductor supporting layer via a blend of the anodizing, re-anodizing, and post- anodizing treatments applied to a thin layer of Al superimposed on selected valve metals (W, Ti, Hf), metal bilayers (W/Ti), or binary metal alloy layers (W-Ti). The achievements are due to (1) the improved self-organization in the PAA thin films during the self-localizing high-current anodization of the upper Al layer at challenging potentials ranging 100 to 250 V and 20 to 5 V, and (2) the enhanced penetration of the alumina barrier layer by the undergrowing metal oxide due to the increasing polarization (re- anodizing). The protrusions of the undergrown metal oxide can be either selectively dissolved away providing perfect nanoholes in the alumina barrier layer or left as formed in the barrier layer and annealed in vacuum to increase their electron conductance and serve as the supports for subsequent metal electrodeposition. Additionally, the in-situ amplitude-modulated constant-current pulse deposition mode combined with the original surface-wiping technique to remove the overdeposited gold allow for smooth nucleation and uniform finishing of perfect arrays of on-substrate gold nanospheres and nanorods, having diameters from 10 to over 250 nm and length up to 2.5 ?m.
关键词： gold nanorods,electrodeposition,barrier layer dissolution,nanodots,porous anodic alumina
更新于2025-09-10 09:29:36
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Rapid Fabrication of Porous Anodic Alumina Films with Large Interpore Distances in an Ethylene Glycol and Ammonium Dihydrogen Phosphate-Based Electrolyte
摘要： Porous anodic alumina (PAA) ?lms have become popular nanotemplates due to the ordered hexagonal pore array structure. The fabrication of well-ordered PAA ?lms with larger interpore distances is still a challenge to date. Here, we develop a unique electrolyte system based on the reaction products of ethylene glycol (EG) with ammonium dihydrogen phosphate (ADP). In the novel electrolytes, stable high-voltage anodization with extremely high current densities (the peak value is close to 300 mA cm?2) can be realized at 400 V or even higher without breakdown. In 5 wt% EG-ADP-based electrolyte containing phosphoric acid, a well-ordered PAA ?lm with an interpore distance of ～610 nm can be fabricated at 250 V at a high growth rate of 1.3 μm · min?1.
关键词： Porous anodic alumina,high-voltage anodization,ethylene glycol,ammonium dihydrogen phosphate,interpore distance
更新于2025-09-09 09:28:46
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Fluorescent nanodiamond array deposition on porous anodized aluminum oxide using asperity assisted capillary force assembly
摘要： Array ordering of nanodiamonds with nitrogen-vacancy centers using porous anodized aluminum oxide (PAAO) templates is studied. Particle sorting and array formation are demonstrated with a polydisperse suspension of irregularly shaped diamonds with 28 nm number mean value diameter. The assembly is governed by a balance of withdrawal speed and evaporation driven particle flux, which is influenced by the asperities of the PAAO surface during the capillary and convective assembly dip-coating process. The resulting structures are dense (50 nm average center separation) isolated (non-touching) nanoparticle arrays with a size distribution that matches the topology of the template surface. The fluorescence signal is detected from arrays with an approximately 1:1 particle/pore filling ratio.
关键词： fluorescent nanodiamond,colloid assembly,porous anodic alumina,templated deposition
更新于2025-09-04 15:30:14