This chapter reviews scanning probe lithography in the production of surface- supported organic a... more This chapter reviews scanning probe lithography in the production of surface- supported organic and biological materials from the perspective of updated products, technical specifications, and potentials. Three methods are described – nanoshaving, nanografting, and nanopen reader and writer – which depend on atomic force microscopy-based nanolithography. The principal steps and resolutions are discussed in conjunction with specific examples of organic and biological nanostructures produced. The advantages and limitations are also summarized. Two techniques based on scanning tunneling microscopy (STM) – electrical field and tunneling electron-induced nanolithography – are also described. The unprecedented resolution of STM-based methods are revealed using the organic nanostructures produced. Finally, future perspectives using scanning probe microscopy-based nanolithography are discussed.
Hybrid metal-organic architectures can be fabricated at the nanoscale using guided self-assembly ... more Hybrid metal-organic architectures can be fabricated at the nanoscale using guided self-assembly on well-defined organic scaffolds to produce layered nanostructures. We have developed a new chemical approach to fabricate nanopatterns of metal nanostructures via electroless metal deposition of nanopatterned silane thin films. First, a surface with different functionalities is prepared with engineered nanopatterns of adhesive and resistive silanes. Next, the organosilane nanopatterns are used as a foundation for site-selective electroless deposition of metals such as iron oxide.
MSM-AFM images of Fe3O4 nanoparticles arranged on glass: individual nanoparticles that are invisi... more MSM-AFM images of Fe3O4 nanoparticles arranged on glass: individual nanoparticles that are invisible in topography frames can be mapped using MSM-AFM.
Porphyrins and metalloporphyrins have unique chemical and electronic properties and thus provide ... more Porphyrins and metalloporphyrins have unique chemical and electronic properties and thus provide useful model structures for studies of nanoscale electronic properties. The rigid planar structures and -conjugated backbones of porphyrins convey robust electrical characteristics. For our investigations, cobaltacarborane porphyrins were synthesized using a ring-opening zwitterionic reaction to produce isomers with selected arrangements of carborane clusters on each macrocycle. Experiments were designed to investigate how the molecular structure influences the self-organization, surface assembly, and conductive properties of three molecular structures with 2, 4, or 8 cobaltacarborane substituents. Current versus voltage (I-V) spectra for designed cobaltacarborane porphyrins deposited on conductive gold substrates were acquired using conductive probe atomic force microscopy (CP-AFM). Characterizations with CP-AFM provide capabilities for obtaining physical measurements and structural information with unprecedented sensitivity. We found that the morphology of cobaltacarborane porphyrin structures formed on surfaces depends on a complex interplay of factors such as the solvent used for dissolution, the nature of the substrate, and the design of the parent molecule. The conductive properties of cobaltacarborane porphyrins were observed to change according to the arrangement of cobaltacarborane substituents. Specifically, the number and placement of the cobaltacarborane ligands on the porphyrin macrocycle affect the interactions that drive porphyrin self-assembly and crystallization. Interestingly, coulombic staircase I-V profiles were detected for a porphyrin with two cobaltacarborane substituents.
ABSTRACT Nanografting is a scanning probe-based technique which takes advantage of the localized ... more ABSTRACT Nanografting is a scanning probe-based technique which takes advantage of the localized tip-surface contact to rapidly and reproducibly inscribe arrays of nanopatterns of thiol self-assembled monolayers (SAMs) and other nanomaterials with nanometer-scale resolution. Scanning probe-based approaches for lithography such as nanografting with self-assembled monolayers extend beyond simple fabrication of nanostructures to enable nanoscale control of the surface composition and chemical reactivity from the bottom-up. Commercial scanning probe instruments typically provide software to control the length, direction, speed and applied force of the scanning motion of a tip, analogous to a pen-plotter. Nanografting is accomplished by force-induced displacement of molecules of a matrix SAM, followed immediately by the surface self-assembly of n-alkanethiol ink molecules from solution. Desired surface chemistries can be patterned by choosing SAMs of different lengths and terminal groups. By combining nanografting and designed spatial selectivity of n-alkanethiols, in situ studies provide new capabilities for nanoscale surface reactions with proteins, nanoparticles or chemical assembly. Methods to precisely arrange molecules on surfaces will contribute to development of molecular device architectures for future nanotechnologies.
Analytical and Bioanalytical Chemistry, Dec 14, 2012
The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic fo... more The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic force microscopy (AFM) and ex situ infrared reflectance-absorption spectroscopy (IRAS). The AFM-based lithography technique of nanografting provided control of the size, geometry, and spatial placement of nanopatterns within self-assembled monolayers (SAMs). Square nanopatterns of carboxylate-terminated SAMs were inscribed within methyl-terminated octadecanethiolate SAMs and activated using carbodiimide/succinimide coupling chemistry. Staphylococcal protein A was immobilized on the activated nanopatterns before exposure to rabbit immunoglobulin G. In situ AFM was used to monitor changes in the topography and friction of the nanopatterns in solution upon protein immobilization. Complementary studies with ex situ IRAS confirmed the surface chemistry that occurred during the steps of SAM activation and subsequent protein immobilization on unpatterned samples. Since carbodiimide/succinimide coupling chemistry can be used for surface attachment of different biomolecules, this protocol shows promise for development of other aqueous-based studies for nanopatterned protein immobilization.
ABSTRACT Morphology changes for copper surfaces exposed to different water parameters were invest... more ABSTRACT Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological chemistries for drinking water, both with and without addition of orthophosphate over a pH range 6.5-9. Copper surfaces treated with orthophosphate as a corrosion inhibitor after 6 and 24 h were evaluated. Tapping mode AFM images revealed dosing of the water with 6 mg/L of orthophosphate was beneficial in retarding the growth of copper by-products. The chemical composition and oxidation state of the surface deposits were characterized with X-ray diffraction (XRD), near edge X-ray absorption fine structure (NEXAFS) spectroscopy and Fourier transform infrared spectroscopy (FTIR).
This chapter reviews scanning probe lithography in the production of surface- supported organic a... more This chapter reviews scanning probe lithography in the production of surface- supported organic and biological materials from the perspective of updated products, technical specifications, and potentials. Three methods are described – nanoshaving, nanografting, and nanopen reader and writer – which depend on atomic force microscopy-based nanolithography. The principal steps and resolutions are discussed in conjunction with specific examples of organic and biological nanostructures produced. The advantages and limitations are also summarized. Two techniques based on scanning tunneling microscopy (STM) – electrical field and tunneling electron-induced nanolithography – are also described. The unprecedented resolution of STM-based methods are revealed using the organic nanostructures produced. Finally, future perspectives using scanning probe microscopy-based nanolithography are discussed.
Hybrid metal-organic architectures can be fabricated at the nanoscale using guided self-assembly ... more Hybrid metal-organic architectures can be fabricated at the nanoscale using guided self-assembly on well-defined organic scaffolds to produce layered nanostructures. We have developed a new chemical approach to fabricate nanopatterns of metal nanostructures via electroless metal deposition of nanopatterned silane thin films. First, a surface with different functionalities is prepared with engineered nanopatterns of adhesive and resistive silanes. Next, the organosilane nanopatterns are used as a foundation for site-selective electroless deposition of metals such as iron oxide.
MSM-AFM images of Fe3O4 nanoparticles arranged on glass: individual nanoparticles that are invisi... more MSM-AFM images of Fe3O4 nanoparticles arranged on glass: individual nanoparticles that are invisible in topography frames can be mapped using MSM-AFM.
Porphyrins and metalloporphyrins have unique chemical and electronic properties and thus provide ... more Porphyrins and metalloporphyrins have unique chemical and electronic properties and thus provide useful model structures for studies of nanoscale electronic properties. The rigid planar structures and -conjugated backbones of porphyrins convey robust electrical characteristics. For our investigations, cobaltacarborane porphyrins were synthesized using a ring-opening zwitterionic reaction to produce isomers with selected arrangements of carborane clusters on each macrocycle. Experiments were designed to investigate how the molecular structure influences the self-organization, surface assembly, and conductive properties of three molecular structures with 2, 4, or 8 cobaltacarborane substituents. Current versus voltage (I-V) spectra for designed cobaltacarborane porphyrins deposited on conductive gold substrates were acquired using conductive probe atomic force microscopy (CP-AFM). Characterizations with CP-AFM provide capabilities for obtaining physical measurements and structural information with unprecedented sensitivity. We found that the morphology of cobaltacarborane porphyrin structures formed on surfaces depends on a complex interplay of factors such as the solvent used for dissolution, the nature of the substrate, and the design of the parent molecule. The conductive properties of cobaltacarborane porphyrins were observed to change according to the arrangement of cobaltacarborane substituents. Specifically, the number and placement of the cobaltacarborane ligands on the porphyrin macrocycle affect the interactions that drive porphyrin self-assembly and crystallization. Interestingly, coulombic staircase I-V profiles were detected for a porphyrin with two cobaltacarborane substituents.
ABSTRACT Nanografting is a scanning probe-based technique which takes advantage of the localized ... more ABSTRACT Nanografting is a scanning probe-based technique which takes advantage of the localized tip-surface contact to rapidly and reproducibly inscribe arrays of nanopatterns of thiol self-assembled monolayers (SAMs) and other nanomaterials with nanometer-scale resolution. Scanning probe-based approaches for lithography such as nanografting with self-assembled monolayers extend beyond simple fabrication of nanostructures to enable nanoscale control of the surface composition and chemical reactivity from the bottom-up. Commercial scanning probe instruments typically provide software to control the length, direction, speed and applied force of the scanning motion of a tip, analogous to a pen-plotter. Nanografting is accomplished by force-induced displacement of molecules of a matrix SAM, followed immediately by the surface self-assembly of n-alkanethiol ink molecules from solution. Desired surface chemistries can be patterned by choosing SAMs of different lengths and terminal groups. By combining nanografting and designed spatial selectivity of n-alkanethiols, in situ studies provide new capabilities for nanoscale surface reactions with proteins, nanoparticles or chemical assembly. Methods to precisely arrange molecules on surfaces will contribute to development of molecular device architectures for future nanotechnologies.
Analytical and Bioanalytical Chemistry, Dec 14, 2012
The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic fo... more The immobilization of proteins on nanopatterned surfaces was investigated using in situ atomic force microscopy (AFM) and ex situ infrared reflectance-absorption spectroscopy (IRAS). The AFM-based lithography technique of nanografting provided control of the size, geometry, and spatial placement of nanopatterns within self-assembled monolayers (SAMs). Square nanopatterns of carboxylate-terminated SAMs were inscribed within methyl-terminated octadecanethiolate SAMs and activated using carbodiimide/succinimide coupling chemistry. Staphylococcal protein A was immobilized on the activated nanopatterns before exposure to rabbit immunoglobulin G. In situ AFM was used to monitor changes in the topography and friction of the nanopatterns in solution upon protein immobilization. Complementary studies with ex situ IRAS confirmed the surface chemistry that occurred during the steps of SAM activation and subsequent protein immobilization on unpatterned samples. Since carbodiimide/succinimide coupling chemistry can be used for surface attachment of different biomolecules, this protocol shows promise for development of other aqueous-based studies for nanopatterned protein immobilization.
ABSTRACT Morphology changes for copper surfaces exposed to different water parameters were invest... more ABSTRACT Morphology changes for copper surfaces exposed to different water parameters were investigated at the nanoscale with atomic force microscopy (AFM), as influenced by changes in pH and the levels of orthophosphate ions. Synthetic water samples were designed to mimic physiological chemistries for drinking water, both with and without addition of orthophosphate over a pH range 6.5-9. Copper surfaces treated with orthophosphate as a corrosion inhibitor after 6 and 24 h were evaluated. Tapping mode AFM images revealed dosing of the water with 6 mg/L of orthophosphate was beneficial in retarding the growth of copper by-products. The chemical composition and oxidation state of the surface deposits were characterized with X-ray diffraction (XRD), near edge X-ray absorption fine structure (NEXAFS) spectroscopy and Fourier transform infrared spectroscopy (FTIR).
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Papers by Jayne Garno