1
|
Wei H, Pascual-Herrero H, Selmani S, Marroquin S, Reginato GD, Guan Z, Ragan R. Nanoantennas report dissipative assembly in oscillatory electric fields. J Colloid Interface Sci 2024; 666:629-638. [PMID: 38615402 DOI: 10.1016/j.jcis.2024.03.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/15/2024] [Accepted: 03/30/2024] [Indexed: 04/16/2024]
Abstract
Understanding driving forces for dissipative, i.e., out of equilibrium, assembly of nanoparticles from colloidal solution at liquid-solid interfaces provides the ability to design external cues for reconfigurable device response. Here electrohydrodynamic flow (EHD) at an electrode-liquid interface is investigated as a dissipative driving force for tuning optical response. EHD results from an oscillatory electric field in a liquid cell between two electrodes and drives assembly of gold nanoparticles (NP) into two-dimensional clusters on electrode surfaces. Clusters are chemically crosslinked during assembly to freeze assemblies for electron microscopy characterization in order to understand how to 'nucleate' cluster formation. Electron microscopy images show deposition with a potential having an amplitude of 5 V and frequency of 100 Hz produces surfaces with isolated NP, which can seed EHD flow. A second deposition step at 5 V and 500 Hz produces a high density of quadramers on surfaces. When exciting near the local surface plasmon resonance of the Au NP clusters formed during assembly, Au NPs serve as in situ nanoantenna reporters of assembly and disassembly. Surface enhanced Raman scattering (SERS) measurements of Au NP capped with 4-mercaptobenzoic acid show order of magnitude signal enhancements occur during cluster formation in the presence of an oscillatory field, which occurs on a time scale of seconds. Confocal fluorescence spectroscopy is used to monitor the dissipative assembly of Au NP over multiple cycles. Results provide insight on how electrical stimuli and seeding local perturbations affects formation of NP clusters and resultant optical response provides insight on how to tune response of optically active surfaces.
Collapse
Affiliation(s)
- Hong Wei
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Héctor Pascual-Herrero
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Serxho Selmani
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Sebastian Marroquin
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Gabriel D Reginato
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Zhibin Guan
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, United States; Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, CA 92697-2580, United States; Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697-2715, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| | - Regina Ragan
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2585, United States; Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, CA 92697-2580, United States; Center for Complex and Active Materials, University of California, Irvine, Irvine, CA 92697, United States.
| |
Collapse
|
2
|
Gold nanoparticle arrays organized in mixed patterns through directed self-assembly of ultrathin block copolymer films on topographic substrates. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
3
|
Thrift WJ, Cabuslay A, Laird AB, Ranjbar S, Hochbaum AI, Ragan R. Surface-Enhanced Raman Scattering-Based Odor Compass: Locating Multiple Chemical Sources and Pathogens. ACS Sens 2019; 4:2311-2319. [PMID: 31416304 DOI: 10.1021/acssensors.9b00809] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Olfaction is important for identifying and avoiding toxic substances in living systems. Many efforts have been made to realize artificial olfaction systems that reflect the capacity of biological systems. A sophisticated example of an artificial olfaction device is the odor compass which uses chemical sensor data to identify odor source direction. Successful odor compass designs often rely on plume-based detection and mobile robots, where active, mechanical motion of the sensor platform is employed. Passive, diffusion-based odor compasses remain elusive as detection of low analyte concentrations and quantification of small concentration gradients from within the sensor platform are necessary. Further, simultaneously identifying multiple odor sources using an odor compass remains an ongoing challenge, especially for similar analytes. Here, we show that surface-enhanced Raman scattering (SERS) sensors overcome these challenges, and we present the first SERS odor compass. Using a grid array of SERS sensors, machine learning analysis enables reliable identification of multiple odor sources arising from diffusion of analytes from one or two localized sources. Specifically, convolutional neural network and support vector machine classifier models achieve over 90% accuracy for a multiple odor source problem. This system is then used to identify the location of an Escherichia coli biofilm via its complex signature of volatile organic compounds. Thus, the fabricated SERS chemical sensors have the needed limit of detection and quantification for diffusion-based odor compasses. Solving the multiple odor source problem with a passive platform opens a path toward an Internet of things approach to monitor toxic gases and indoor pathogens.
Collapse
|
4
|
Jin CM, Lee W, Kim D, Kang T, Choi I. Photothermal Convection Lithography for Rapid and Direct Assembly of Colloidal Plasmonic Nanoparticles on Generic Substrates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1803055. [PMID: 30294867 DOI: 10.1002/smll.201803055] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/11/2018] [Indexed: 06/08/2023]
Abstract
Controlled assembly of colloidal nanoparticles onto solid substrates generally needs to overcome their thermal diffusion in water. For this purpose, several techniques that are based on chemical bonding, capillary interactions with substrate patterning, optical force, and optofluidic heating of light-absorbing substrates are proposed. However, the direct assembly of colloidal nanoparticles on generic substrates without chemical linkers and substrate patterning still remains challenging. Here, photothermal convection lithography is proposed, which allows the rapid placement of colloidal nanoparticles onto the surface of diverse solid substrates. It is based on local photothermal heating of colloidal nanoparticles by resonant light focusing without substrate heating, which induces convective flow. The convective flow, then, forces the colloidal nanoparticles to assemble at the illumination point of light. The size of the assembly is increased by either increasing the light intensity or illumination time. It is shown that three types of colloidal gold nanoparticles with different shapes (rod, star, and sphere) can be uniformly assembled by the proposed method. Each assembly with a diameter of tens of micrometers can be completed within a minute and its patterned arrays can also be achieved rapidly.
Collapse
Affiliation(s)
- Chang Min Jin
- Department of Life Science, University of Seoul, Seoul, 130-743, Republic of Korea
| | - Wooju Lee
- Department of Mechanical Engineering, Sogang University, Seoul, 121-742, Republic of Korea
| | - Dongchoul Kim
- Department of Mechanical Engineering, Sogang University, Seoul, 121-742, Republic of Korea
| | - Taewook Kang
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, 121-742, Republic of Korea
| | - Inhee Choi
- Department of Life Science, University of Seoul, Seoul, 130-743, Republic of Korea
| |
Collapse
|
5
|
Hsu SW, Rodarte AL, Som M, Arya G, Tao AR. Colloidal Plasmonic Nanocomposites: From Fabrication to Optical Function. Chem Rev 2018; 118:3100-3120. [DOI: 10.1021/acs.chemrev.7b00364] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Su-Wen Hsu
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, MC 0448, La Jolla, California 92039-0448, United States
| | - Andrea L. Rodarte
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, MC 0448, La Jolla, California 92039-0448, United States
| | - Madhura Som
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, MC 0448, La Jolla, California 92039-0448, United States
| | - Gaurav Arya
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, MC 0448, La Jolla, California 92039-0448, United States
| | - Andrea R. Tao
- Department of NanoEngineering, University of California, San Diego, 9500 Gilman Drive, MC 0448, La Jolla, California 92039-0448, United States
| |
Collapse
|
6
|
Thrift WJ, Nguyen CQ, Darvishzadeh-Varcheie M, Zare S, Sharac N, Sanderson RN, Dupper TJ, Hochbaum AI, Capolino F, Abdolhosseini Qomi MJ, Ragan R. Driving Chemical Reactions in Plasmonic Nanogaps with Electrohydrodynamic Flow. ACS NANO 2017; 11:11317-11329. [PMID: 29053246 DOI: 10.1021/acsnano.7b05815] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoparticles from colloidal solution-with controlled composition, size, and shape-serve as excellent building blocks for plasmonic devices and metasurfaces. However, understanding hierarchical driving forces affecting the geometry of oligomers and interparticle gap spacings is still needed to fabricate high-density architectures over large areas. Here, electrohydrodynamic (EHD) flow is used as a long-range driving force to enable carbodiimide cross-linking between nanospheres and produces oligomers exhibiting sub-nanometer gap spacing over mm2 areas. Anhydride linkers between nanospheres are observed via surface-enhanced Raman scattering (SERS) spectroscopy. The anhydride linkers are cleavable via nucleophilic substitution and enable placement of nucleophilic molecules in electromagnetic hotspots. Atomistic simulations elucidate that the transient attractive force provided by EHD flow is needed to provide a sufficient residence time for anhydride cross-linking to overcome slow reaction kinetics. This synergistic analysis shows assembly involves an interplay between long-range driving forces increasing nanoparticle-nanoparticle interactions and probability that ligands are in proximity to overcome activation energy barriers associated with short-range chemical reactions. Absorption spectroscopy and electromagnetic full-wave simulations show that variations in nanogap spacing have a greater influence on optical response than variations in close-packed oligomer geometry. The EHD flow-anhydride cross-linking assembly method enables close-packed oligomers with uniform gap spacings that produce uniform SERS enhancement factors. These results demonstrate the efficacy of colloidal driving forces to selectively enable chemical reactions leading to future assembly platforms for large-area nanodevices.
Collapse
Affiliation(s)
- William J Thrift
- Department of Chemical Engineering and Materials Science, University of California, Irvine , Irvine, California 92697-2575, United States
| | - Cuong Q Nguyen
- Department of Chemical Engineering and Materials Science, University of California, Irvine , Irvine, California 92697-2575, United States
| | - Mahsa Darvishzadeh-Varcheie
- Department of Electrical Engineering and Computer Science, University of California, Irvine , Irvine, California 92697-2625, United States
| | - Siavash Zare
- Department of Civil and Environmental Engineering, University of California, Irvine , Irvine, California 92697-2175, United States
| | - Nicholas Sharac
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Robert N Sanderson
- Department of Physics and Astronomy, University of California, Irvine , Irvine, California 92697-4575, United States
| | - Torin J Dupper
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Allon I Hochbaum
- Department of Chemical Engineering and Materials Science, University of California, Irvine , Irvine, California 92697-2575, United States
- Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States
| | - Filippo Capolino
- Department of Electrical Engineering and Computer Science, University of California, Irvine , Irvine, California 92697-2625, United States
| | | | - Regina Ragan
- Department of Chemical Engineering and Materials Science, University of California, Irvine , Irvine, California 92697-2575, United States
| |
Collapse
|
7
|
Darvishzadeh-Varcheie M, Guclu C, Ragan R, Boyraz O, Capolino F. Electric field enhancement with plasmonic colloidal nanoantennas excited by a silicon nitride waveguide. OPTICS EXPRESS 2016; 24:28337-28352. [PMID: 27958544 DOI: 10.1364/oe.24.028337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate the feasibility of CMOS-compatible optical structures to develop novel integrated spectroscopy systems. We show that local field enhancement is achievable utilizing dimers of plasmonic nanospheres that can be assembled from colloidal solutions on top of a CMOS-compatible optical waveguide. The resonant dimer nanoantennas are excited by modes guided in the integrated silicon nitride waveguide. Simulations show that 100-fold electric field enhancement builds up in the dimer gap as compared to the waveguide evanescent field amplitude at the same location. We investigate how the field enhancement depends on dimer location, orientation, distance and excited waveguide mode.
Collapse
|
8
|
Guo Q, Xu M, Yuan Y, Gu R, Yao J. Self-Assembled Large-Scale Monolayer of Au Nanoparticles at the Air/Water Interface Used as a SERS Substrate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4530-7. [PMID: 27101361 DOI: 10.1021/acs.langmuir.5b04393] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Self-assembly of metal nanoparticles has attracted considerable attention because of its unique applications in technologies such as plasmonics, surface-enhanced optics, sensors, and catalysts. However, fabrication of ordered nanoparticle structures remains a significant challenge. Thus, developing an efficient approach for the assembly of large-scale Au nanoparticles films for theoretical studies and for various applications is highly desired. In this paper, a facial approach for fabricating a monolayer film of Au nanoparticles was developed successfully. Using the surfactant polyvinylpyrrolidone (PVP), a large-scale monolayer film of well-ordered, uniform-sized Au nanoparticles was fabricated at the air/water interface. The film exhibited a two-dimensional (2D) hexagonal close-packed (HCP) structure having interparticle gaps smaller than 2 nm. These gaps generated numerous uniform "hot spots" for surface-enhanced Raman scattering (SERS) activity. The as-prepared monolayer film could be transferred to a solid substrate for use as a suitable SERS substrate with high activity, high uniformity, and high stability. The low spot-to-spot and substrate-to-substrate variations of intensity (<10%), the large surface enhancement factor (∼10(6)), and the high stability (∼45 days) make the substrate suitable for SERS measurements. Transfer of the monolayer film onto a glassy carbon electrode produced an Au electrode with clean, well-defined nanostructure suitable for electrochemical SERS measurements. The adsorption process of ionic liquids on the electrode with the monolayer film is similar to that on bulk metal electrodes. The present strategy provides an effective way for self-assembly of Au nanoparticles into well-defined nanostructures that may form optimal reproducible SERS substrates for quantitative analysis. It also provides an electrode with clean, well-defined nanostructure for electrochemical investigations.
Collapse
Affiliation(s)
- Qinghua Guo
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| | - Minmin Xu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| | - Yaxian Yuan
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| | - Renao Gu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| | - Jianlin Yao
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| |
Collapse
|
9
|
Jiang B, Nykypanchuk D, Endoh MK, Chen X, Qian B, Kisslinger K, Koga T, Parise JB, Grubbs RB. Phase Behavior of Alkyne-Functionalized Styrenic Block Copolymer/Cobalt Carbonyl Adducts and in Situ Formation of Magnetic Nanoparticles by Thermolysis. Macromolecules 2016. [DOI: 10.1021/acs.macromol.5b02515] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
| | - Dmytro Nykypanchuk
- Center
for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | | | | | | | - Kim Kisslinger
- Center
for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | | | | | | |
Collapse
|
10
|
Electroless deposition of SERS active Au-nanostructures on variety of metallic substrates. BIOCHIP JOURNAL 2013. [DOI: 10.1007/s13206-013-7409-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
11
|
Campione S, Guclu C, Ragan R, Capolino F. Fano resonances in metasurfaces made of linear trimers of plasmonic nanoparticles. OPTICS LETTERS 2013; 38:5216-5219. [PMID: 24322221 DOI: 10.1364/ol.38.005216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate Fano resonances in planar two-dimensional periodic arrays of linear trimers of plasmonic nanoparticles that appear under plane wave incidence. The observed Fano resonances are associated to resonances belonging to the trimer (metamolecule) itself, where some are found to be strongly affected by the array periodicity. We observe that array-dependent resonances appearing for oblique incidence are resistant to losses, whereas narrow dipolar-like Fano resonances associated mainly to the metamolecule, which appear also under normal incidence, disappear when losses are too high. In particular, we prove the latter by theoretical (dipolar approximation) and full-wave simulations, in good agreement. We propose that the use of very low-loss plasmonic materials or the use of gain materials to mitigate plasmonic losses may lead to (high-quality factor) dipolar-like Fano resonances under normal incidence, exhibiting a certain degree of fabrication defect tolerance, which might be employed to improve sensors, lasing, switching, and nonlinear devices, for example.
Collapse
|
12
|
Gao B, Rozin MJ, Tao AR. Plasmonic nanocomposites: polymer-guided strategies for assembling metal nanoparticles. NANOSCALE 2013; 5:5677-5691. [PMID: 23703218 DOI: 10.1039/c3nr01091k] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Noble metal nanoparticles that support localized surface plasmon resonances (LSPRs) have the unique ability to manipulate and confine light at subwavelength dimensions. Utilizing these capabilities in devices and coatings requires the controlled organization of metal nanoparticles into ordered or hierarchical structures. Polymer grafts can be used as assembly-regulating molecules that bind to the nanoparticle surface and guide nanoparticle organization in solution, at interfaces, and within condensed phases. Here, we present an overview of polymer-directed assembly of plasmonic nanoparticles. We discuss how polymer grafts can be used to control short-range nanoparticle interactions that dictate interparticle gap distance and orientation. We also discuss how condensed polymer grafts can be used to control long-range order within condensed nanoparticle-polymer blends. The assembly of shaped plasmonic nanoparticles that have potential applications in enhanced spectroscopy and optical metamaterials is highlighted. We end with a summary of promising new directions toward the fabrication of plasmonic nanocomposites that are responsive and possess three-dimensional order.
Collapse
Affiliation(s)
- Bo Gao
- NanoEngineering Department, University of California, San Diego, 9500 Gilman Dr #0448, La Jolla, CA 92093-0448, USA
| | | | | |
Collapse
|
13
|
Campione S, Adams SM, Ragan R, Capolino F. Comparison of electric field enhancements: linear and triangular oligomers versus hexagonal arrays of plasmonic nanospheres. OPTICS EXPRESS 2013; 21:7957-7973. [PMID: 23571888 DOI: 10.1364/oe.21.007957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We investigate local electromagnetic field enhancements in oligomers of plasmonic nanospheres. We first evaluate via full-wave simulations the field between spheres in several oligomer systems: linear dimers, linear trimers, trimers 60°, trimers 90° and linear quadrumers. To gain a better understanding of the field enhancement values, we compare the results with local fields in a hexagonal close-packed (HCP) configuration with same structural dimensions. We then inter-relate the field enhancement values found via full-wave simulations to SERS enhancements of actual fabricated self-assembled oligomers. We find that linear oligomers provide the largest field enhancement values. Finally, we provide closed-form formulas for the prediction of the resonance frequency responsible for field enhancement in linear oligomers, namely dimers, trimers and quadrumers, modeling each nanosphere as a single electric dipole. These formulas provide with resonance values less than 7% shifted when compared to full-wave results even when the gap between spheres is only about one fifth of the radius, showing the powerfulness of dipolar approximations. The results shown in this paper demonstrate that ad hoc clusters of nanospheres can be designed and fabricated to obtain larger field enhancements than with the HCP structure and this may pave the way for the development of improved sensors for molecular spectroscopy.
Collapse
Affiliation(s)
- Salvatore Campione
- Department of Electrical Engineering and Computer Science, University of California, Irvine, CA 92697, USA
| | | | | | | |
Collapse
|
14
|
Adams SM, Campione S, Capolino F, Ragan R. Directing cluster formation of Au nanoparticles from colloidal solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4242-4251. [PMID: 23472803 DOI: 10.1021/la3051719] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Discrete clusters of closely spaced Au nanoparticles can be utilized in devices from photovoltaics to molecular sensors because of the formation of strong local electromagnetic field enhancements when illuminated near their plasmon resonance. In this study, scalable, chemical self-organization methods are shown to produce Au nanoparticle clusters with uniform nanometer interparticle spacing. The performance of two different methods, namely electrophoresis and diffusion, for driving the attachment of Au nanoparticles using a chemical cross-linker on chemically patterned domains of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) thin films are evaluated. Significantly, electrophoresis is found to produce similar surface coverage as diffusion in 1/6th of the processing time with an ~2-fold increase in the number of Au nanoparticles forming clusters. Furthermore, average interparticle spacing within Au nanoparticle clusters was found to decrease from 2-7 nm for diffusion deposition to approximately 1-2 nm for electrophoresis deposition, and the latter method exhibited better uniformity with most clusters appearing to have about 1 nm spacing between nanoparticles. The advantage of such fabrication capability is supported by calculations of local electric field enhancements using electromagnetic full-wave simulations from which we can estimate surface-enhanced Raman scattering (SERS) enhancements. In particular, full-wave results show that the maximum SERS enhancement, as estimated here as the fourth power of the local electric field, increases by a factor of 100 when the gap goes from 2 to 1 nm, reaching values as large as 10(10), strengthening the usage of electrophoresis versus diffusion for the development of molecular sensors.
Collapse
Affiliation(s)
- Sarah M Adams
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, United States
| | | | | | | |
Collapse
|
15
|
Ma R, Lu N, Liu L, Wang Y, Shi S, Chi L. Fabrication of single gold particle arrays with pattern directed electrochemical deposition. ACS APPLIED MATERIALS & INTERFACES 2012; 4:3779-3783. [PMID: 22856546 DOI: 10.1021/am3010972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A simple and efficient method for fabricating gold nanoparticle (AuNP) arrays is developed. With this method, the AuNP arrays are fabricated by taking an electrochemical deposition (ECD) process on the ITO substrate, which is initially patterned with nanoimprint lithography (NIL). The stamp for NIL is fabricated by the cost-efficient nanosphere lithography (NSL). The size of the AuNPs can be adjusted by varying the potential and duration of ECD. In this work, the diameters of AuNPs are varied from 130 to 420 nm. The AuNP arrays can be readily extended to other conductive substrates, which may be applied for detecting and sensing.
Collapse
|
16
|
Adams SM, Campione S, Caldwell JD, Bezares FJ, Culbertson JC, Capolino F, Ragan R. Non-lithographic SERS substrates: tailoring surface chemistry for Au nanoparticle cluster assembly. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:2239-2249. [PMID: 22528745 DOI: 10.1002/smll.201102708] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/13/2012] [Indexed: 05/31/2023]
Abstract
Near-field plasmonic coupling and local field enhancement in metal nanoarchitectures, such as arrangements of nanoparticle clusters, have application in many technologies from medical diagnostics, solar cells, to sensors. Although nanoparticle-based cluster assemblies have exhibited signal enhancements in surface-enhanced Raman scattering (SERS) sensors, it is challenging to achieve high reproducibility in SERS response using low-cost fabrication methods. Here an innovative method is developed for fabricating self-organized clusters of metal nanoparticles on diblock copolymer thin films as SERS-active structures. Monodisperse, colloidal gold nanoparticles are attached via a crosslinking reaction on self-organized chemically functionalized poly(methyl methacrylate) domains on polystyrene-block-poly(methyl methacrylate) templates. Thereby nanoparticle clusters with sub-10-nanometer interparticle spacing are achieved. Varying the molar concentration of functional chemical groups and crosslinking agent during the assembly process is found to affect the agglomeration of Au nanoparticles into clusters. Samples with a high surface coverage of nanoparticle cluster assemblies yield relative enhancement factors on the order of 10⁹ while simultaneously producing uniform signal enhancements in point-to-point measurements across each sample. High enhancement factors are associated with the narrow gap between nanoparticles assembled in clusters in full-wave electromagnetic simulations. Reusability for small-molecule detection is also demonstrated. Thus it is shown that the combination of high signal enhancement and reproducibility is achievable using a completely non-lithographic fabrication process, thereby producing SERS substrates having high performance at low cost.
Collapse
Affiliation(s)
- Sarah M Adams
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA 92697, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Lee CH, Li P. pH-induced formation of various hierarchical structures from amphiphilic core–shell nanotubes. RSC Adv 2012. [DOI: 10.1039/c2ra00959e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
18
|
Pavan MJ, Shenhar R. Two-dimensional nanoparticle organization using block copolymer thin films as templates. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm02853c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
19
|
Tian F, Cheng N, Nouvel N, Geng J, Scherman OA. Site-selective immobilization of colloids on Au substrates via a noncovalent supramolecular "handcuff". LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5323-5328. [PMID: 20337412 DOI: 10.1021/la9033386] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have examined hierarchical supramolecular structure in the formation of colloidal arrays by immobilizing monodispersed naphthalene-functionalized colloids onto Au substrates bearing viologen moieties using the macrocyclic host molecule cucurbit[8]uril as a supramolecular "handcuff". Naphthalene-functionalized poly(methyl methacrylate)- and polystyrene-based colloids were synthesized by soap-free emulsion polymerization and characterized by dynamic light scattering and scanning electron microscopy to realize the colloidal arrays and to facilitate direct macroscopic imaging. The formation of host-stabilized ternary complexes on the surface of naphthalene-functionalized microspheres in colloidal suspension was verified by titration of a preformed viologen-CB[8] complex and followed by zeta potential measurements. Patterned self-assembled monolayers of a viologen derivative on Au substrates were formed by backfilling viologen-modified thiols after spontaneous chemisorption of "protective" alkylthiols by microcontact printing. After the initial complexation of CB[8] onto the viologen derivative on the Au substrates, monolayers of colloids with both 1D and 2D patterns could be formed and characterized by contact angle measurement, optical microscopy, and scanning electron microscopy. Control experiments indicated that no colloids were attached to the Au substrate after moderate washing by water if (1) CB[8] was replaced by a smaller analogue of the macrocyclic host, CB[6] or CB[7], (2) colloids without naphthalene-functionalities on the periphery were employed, or (3) alkanethiol was used entirely instead of viologenthiol to protect the Au substrate. These results suggest that the supramolecular ternary complexes were key to successfully bind the colloids onto the Au substrates with the CB[8] acts as a supramolecular "handcuff". The fundamental expertise gained from the study of these materials is believed to facilitate progress in the field of smart materials and wet nanotechnology and lead to the preparation of controlled reversible architectures on surfaces.
Collapse
Affiliation(s)
- Feng Tian
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | | | | | | | | |
Collapse
|
20
|
Fang XL, Li Y, Chen C, Kuang Q, Gao XZ, Xie ZX, Xie SY, Huang RB, Zheng LS. pH-induced simultaneous synthesis and self-assembly of 3D layered beta-FeOOH nanorods. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2745-2750. [PMID: 19957938 DOI: 10.1021/la902765p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Higher-ordered architectures self-assembly of nanomaterials have recently attracted increasing attention. In this work, we report a spontaneous and efficient route to simultaneous synthesis and self-assembly of 3D layered beta-FeOOH nanorods depending on a pH-induced strategy, in which the continuous change of pH is achieved by hydrolysis of FeCl(3).6H(2)O in the presence of urea under hydrothermal conditions. The electron microscopy observations reveal that the square-prismic beta-FeOOH nanorods are self-assembled in a side-by-side fashion to form highly oriented 2D nanorod arrays, and the 2D nanorod arrays are further stacked in a face-to-face fashion to form the final 3D layered architectures. On the basis of time-dependent experiments, a multistage reaction mechanism for the formation of the 3D layered beta-FeOOH nanorods architecture is presented, involving the fast growth and synchronous self-assembly of the nanorods toward 1D, 2D, and 3D spontaneously. The experimental evidence further demonstrates that the urea-decomposition-dependent pH continuously changing in the solution, spontaneously altering the driving force competition between the electrostatic repulsive force and the attractive van der Waals force among the nanorods building blocks, is the essential factor to influence the self-assembly of the beta-FeOOH nanorods from 1D to 3D.
Collapse
Affiliation(s)
- Xiao-Liang Fang
- State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Jiang L, Wang W, Fuchs H, Chi L. One-dimensional arrangement of gold nanoparticles with tunable interparticle distance. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2819-2822. [PMID: 19842113 DOI: 10.1002/smll.200900770] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Lin Jiang
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster and Center for Nanotechnology (CeNTech), Münster 48149, Germany
| | | | | | | |
Collapse
|