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Mechanical Engineering Publications

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Full-Text Articles in Nanoscience and Nanotechnology

Protein-Assisted Scalable Mechanochemical Exfoliation Of Few-Layer Biocompatible Graphene Nanosheets, Deepak-George Thomas, Steven De-Alwis, Shalabh Gupta, Vitalij K. Pecharsky, Deyny Mendivelso-Perez, Reza Montazami, Emily A. Smith, Nicole N. Hashemi Mar 2021

Protein-Assisted Scalable Mechanochemical Exfoliation Of Few-Layer Biocompatible Graphene Nanosheets, Deepak-George Thomas, Steven De-Alwis, Shalabh Gupta, Vitalij K. Pecharsky, Deyny Mendivelso-Perez, Reza Montazami, Emily A. Smith, Nicole N. Hashemi

Mechanical Engineering Publications

A facile method to produce few-layer graphene (FLG) nanosheets is developed using protein-assisted mechanical exfoliation. The predominant shear forces that are generated in a planetary ball mill facilitate the exfoliation of graphene layers from graphite flakes. The process employs a commonly known protein, bovine serum albumin (BSA), which not only acts as an effective exfoliation agent but also provides stability by preventing restacking of the graphene layers. The latter is demonstrated by the excellent long-term dispersibility of exfoliated graphene in an aqueous BSA solution, which exemplifies a common biological medium. The development of such potentially scalable and toxin-free methods is ...


All-Graphene-Based Open Fluidics For Pumpless, Small-Scale Fluid Transport Via Laser-Controlled Wettability Patterning, Lucas S. Hall, Dohgyu Hwang, Bolin Chen, Bryan Van Belle, Zachary T. Johnson, John A. Hondred, Carmen L. Gomes, Michael D. Bartlett, Jonathan C. Claussen Jan 2021

All-Graphene-Based Open Fluidics For Pumpless, Small-Scale Fluid Transport Via Laser-Controlled Wettability Patterning, Lucas S. Hall, Dohgyu Hwang, Bolin Chen, Bryan Van Belle, Zachary T. Johnson, John A. Hondred, Carmen L. Gomes, Michael D. Bartlett, Jonathan C. Claussen

Mechanical Engineering Publications

Open microfluidics have emerged as a low-cost, pumpless alternative strategy to conventional microfluidics for delivery of fluid for a wide variety of applications including rapid biochemical analysis and medical diagnosis. However, creating open microfluidics by tuning the wettability of surfaces typically requires sophisticated cleanroom processes that are unamenable to scalable manufacturing. Herein, we present a simple approach to develop open microfluidic platforms by manipulating the surface wettability of spin-coated graphene ink films on flexible polyethylene terephthalate via laser-controlled patterning. Wedge-shaped hydrophilic tracks surrounded by superhydrophobic walls are created within the graphene films by scribing micron-sized grooves into the graphene with ...


Sense–Analyze–Respond–Actuate (Sara) Paradigm: Proof Of Concept System Spanning Nanoscale And Macroscale Actuation For Detection Of Escherichia Coli In Aqueous Media, Cassie A. Giacobassi, Daniela A. Oliveira, Cicero C. Pola, Dong Xiang, Yifan Tang, Shoumen Palit Austin Datta, Eric S. Mclamore, Carmen L. Gomes Jan 2021

Sense–Analyze–Respond–Actuate (Sara) Paradigm: Proof Of Concept System Spanning Nanoscale And Macroscale Actuation For Detection Of Escherichia Coli In Aqueous Media, Cassie A. Giacobassi, Daniela A. Oliveira, Cicero C. Pola, Dong Xiang, Yifan Tang, Shoumen Palit Austin Datta, Eric S. Mclamore, Carmen L. Gomes

Mechanical Engineering Publications

Foodborne pathogens are a major concern for public health. We demonstrate for the first time a partially automated sensing system for rapid (~17 min), label-free impedimetric detection of Escherichia coli spp. in food samples (vegetable broth) and hydroponic media (aeroponic lettuce system) based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) nanobrushes. This proof of concept (PoC) for the Sense-Analyze-Respond-Actuate (SARA) paradigm uses a biomimetic nanostructure that is analyzed and actuated with a smartphone. The bio-inspired soft material and sensing mechanism is inspired by binary symbiotic systems found in nature, where low concentrations of bacteria are captured from complex matrices by brush actuation ...


3d Interdigitated Vertically Aligned Carbon Nanotube Electrodes For Electrochemical Impedimetric Biosensing, Benjamin J. Brownlee, Jonathan C. Claussen, Brian D. Iverson Sep 2020

3d Interdigitated Vertically Aligned Carbon Nanotube Electrodes For Electrochemical Impedimetric Biosensing, Benjamin J. Brownlee, Jonathan C. Claussen, Brian D. Iverson

Mechanical Engineering Publications

Advances in nanomaterials, combined with electrochemical impedance spectroscopy (EIS), have allowed electrochemical biosensors to have high sensitivity while remaining label-free, enabling the potential for portable diagnosis at the point-of-care. We report porous, 3D vertically aligned carbon nanotube (VACNT) electrodes with underlying chromium electrical leads for impedance-based biosensing. The electrodes are characterized by electrode height (5, 25, and 80 μm), gap width (15 and 25 μm), and geometry (interdigitated and serpentine) using scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The protein streptavidin is functionalized onto VACNT electrodes for detection of biotin, as confirmed by fluorescence microscopy. EIS is ...


Formation Of Size And Density Controlled Nanostructures By Galvanic Displacement, Minh Tran, Sougata Roy, Steven Kmiec, Alison Whale, Steve W. Martin, Sriram Sundararajan, Sonal Padalkar Mar 2020

Formation Of Size And Density Controlled Nanostructures By Galvanic Displacement, Minh Tran, Sougata Roy, Steven Kmiec, Alison Whale, Steve W. Martin, Sriram Sundararajan, Sonal Padalkar

Mechanical Engineering Publications

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB). An approach involving cyclic exposure to HF acid regulated the nanostructure density. Further, the use of surfactants generated monodisperse nanoparticles in the initial stages of the ...


Development And Optimization Of Ph-Responsive Plga-Chitosan Nanoparticles For Triggered Release Of Antimicrobials, Cicero C. Pola, Allan R.F. Moraes, Eber A.A. Medeiros, Reinaldo F. Teófilo, Nilda F.F. Soares, Carmen L. Gomes Oct 2019

Development And Optimization Of Ph-Responsive Plga-Chitosan Nanoparticles For Triggered Release Of Antimicrobials, Cicero C. Pola, Allan R.F. Moraes, Eber A.A. Medeiros, Reinaldo F. Teófilo, Nilda F.F. Soares, Carmen L. Gomes

Mechanical Engineering Publications

The aim of this work was to develop and optimize a pH-responsive nanoparticle based on poly(D,L-lactide-co-glycolide) (PLGA) and chitosan (CHIT) for delivery of natural antimicrobial using trans-cinnamaldehyde (TCIN) as a model compound. The optimization was performed using a central composite design and the desirability function approach. The optimized levels of variables considering all significant responses were 4% (w/w) of TCIN and 6.75% (w/w) of CHIT. After, optimized nanoparticles were produced and characterized according to their physicochemical properties and their antimicrobial activity against SalmonellaTyphimurium and Staphylococcus aureus. Optimized nanoparticles characterization indicated a satisfactory TCIN ...


Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen Aug 2019

Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen

Mechanical Engineering Publications

A multi-step approach is described for the fabrication of multi-layer graphene-based electrodes without the need for ink binders or post-print annealing. Graphite and nanoplatelet graphene were chemically exfoliated using a modified Hummers’ method and the dried material was thermally expanded. Expanded materials were used in a 3D printed mold and stamp to create laminate electrodes on various substrates. The laminates were examined for potential sensing applications using model systems of peroxide (H2O2) and enzymatic glucose detection. Within the context of these two assay systems, platinum nanoparticle electrodeposition and oxygen plasma treatment were examined as methods for improving sensitivity. Electrodes made ...


Porous Wood Monoliths Decorated With Platinum Nano-Urchins As Catalysts For Underwater Micro-Vehicle Propulsion Via H2o2 Decomposition, Bolin Chen, Ahmed Gsalla, Anand Gaur, Yu Hui Lui, Xiaohui Tang, Jason Geder, Marius Pruessner, Brian J. Melde, Igor L. Medintz, Behrouz Shafei, Shan Hu, Jonathan C. Claussen Jun 2019

Porous Wood Monoliths Decorated With Platinum Nano-Urchins As Catalysts For Underwater Micro-Vehicle Propulsion Via H2o2 Decomposition, Bolin Chen, Ahmed Gsalla, Anand Gaur, Yu Hui Lui, Xiaohui Tang, Jason Geder, Marius Pruessner, Brian J. Melde, Igor L. Medintz, Behrouz Shafei, Shan Hu, Jonathan C. Claussen

Mechanical Engineering Publications

Porous carbon is becoming an important and promising high-surface area scaffold material for various energy-based applications including catalysis. Here we demonstrate the growth of urchin-like platinum nanoparticles (PtNPs) on carbon monoliths derived from basswood that work as catalysts for micro underwater vehicle (MUV) propulsion via H2O2 decomposition. The carbon monoliths were constructed of natural basswood that was carbonized in argon (Ar) and subjected to a subsequent CO2 activation process that rendered the material into a hardened 3D porous activated carbonized wood (ACW) with inner channel voids measuring 10-70 μm in diameter. The PtNP nanourchins (500 nm or less in total ...


Hybrid Nanosecond Laser Processing And Heat Treatment For Rapid Preparation Of Super-Hydrophobic Copper Surface, Linxu Ma, Lina Wang, Chengying Li, Jian Guo, Pranav Shrotriya, Cui Deng, Jingnan Zhao Jun 2019

Hybrid Nanosecond Laser Processing And Heat Treatment For Rapid Preparation Of Super-Hydrophobic Copper Surface, Linxu Ma, Lina Wang, Chengying Li, Jian Guo, Pranav Shrotriya, Cui Deng, Jingnan Zhao

Mechanical Engineering Publications

The super-hydrophobic copper surface was obtained by using a nanosecond pulsed laser. Different micro- and nano-structures were fabricated by changing the laser scanning interval and scanning speed, before heating in an electric heater at 150 °C for two hours to explore the effect of laser parameters and heat treatment on the wettability of the copper surface. It was found that the laser-treated copper surface is super-hydrophilic, and then, after the heat treatment, the surface switches to hydrophobic or even super-hydrophobic. The best super-hydrophobic surface’s apparent contact angle (APCA) was 155.6°, and the water sliding angle (WSA) was 4 ...


Enhanced Electrochemical Biosensor And Supercapacitor With 3d Porous Architectured Graphene Via Salt Impregnated Inkjet Maskless Lithography, John A. Hondred, Igor L. Medintz, Jonathan C. Claussen Jan 2019

Enhanced Electrochemical Biosensor And Supercapacitor With 3d Porous Architectured Graphene Via Salt Impregnated Inkjet Maskless Lithography, John A. Hondred, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Advances in solution-phase graphene patterning has provided a facile route for rapid, low-cost and scalable manufacturing of electrochemical devices, even on flexible substrates. While graphene possesses advantageous electrochemical properties of high surface area and fast heterogenous charge transport, these properties are attributed to the edge planes and defect sites, not the basal plane. Herein, we demonstrate enhancement of the electroactive nature of patterned solution-phase graphene by increasing the porosity and edge planes through the construction of a multidimensional architecture via salt impregnated inkjet maskless lithography (SIIML) and CO2 laser annealing. Various sized macroscale pores (<25 to ∼250 μm) are patterned directly in the graphene surface by incorporating porogens (i.e., salt crystals) in the ...


Electrochemical Cotinine Sensing With A Molecularly Imprinted Polymer On A Graphene-Platinum Nanoparticle Modified Carbon Electrode Towards Cigarette Smoke Exposure Monitoring, Kshama Parate, Chandran Karunakaran, Jonathan C. Claussen Jan 2019

Electrochemical Cotinine Sensing With A Molecularly Imprinted Polymer On A Graphene-Platinum Nanoparticle Modified Carbon Electrode Towards Cigarette Smoke Exposure Monitoring, Kshama Parate, Chandran Karunakaran, Jonathan C. Claussen

Mechanical Engineering Publications

Cotinine, a metabolite of nicotine, has shown promise as a biomarker for the detection of tobacco use and smoke exposure due its ability to persist in human bodily fluids for days (ca. 4-5 days) after tobacco consumption. However, current cotinine detection strategies primarily include arduous laboratory sensing methods or qualitative in-field biosensing devices. Herein, we report an electrochemical cotinine sensor based on a selective molecularly-imprinted polymer (MIP) electrodeposited on a screen-printed carbon electrode (SPCE) modified with graphene flakes and platinum nanoparticles (PtNPs). The PtNP-graphene modified SPCE exhibited a 4-fold increase in electrochemical sensitivity (10 µA to 40 µA) during ferryicyanide ...


Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen Nov 2018

Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen

Mechanical Engineering Publications

Flexible graphene electronics are rapidly gaining interest, but their widespread implementation has been impeded by challenges with ink preparation, ink printing, and post-print annealing processes. Laser-induced graphene (LIG) promises a facile alternative by creating flexible graphene electronics on polyimide substrates through a one-step laser writing fabrication method. Herein we demonstrate the use of LIG, created through a low-cost UV laser, for electrochemical ion selective sensing of plant-available nitrogen (i.e., both ammonium and nitrate ions: NH4+ and NO3-) in soil samples. The laser used to create the LIG was operated at distinct pulse rates (10, 20, 30, 40, and 50 ...


Fluorescent Nanodiamonds: Past, Present, And Future, Masfer H. Alkahtani, Fahad Alghannam, Linkun Jiang, Abdulrahman Almethen, Arfaan A. Rampersaud, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Philip R. Hemmer Jul 2018

Fluorescent Nanodiamonds: Past, Present, And Future, Masfer H. Alkahtani, Fahad Alghannam, Linkun Jiang, Abdulrahman Almethen, Arfaan A. Rampersaud, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Philip R. Hemmer

Mechanical Engineering Publications

Multi-color fluorescent nanodiamonds (FNDs) containing a variety of color centers are promising fluorescent markers for biomedical applications. Compared to colloidal quantum dots and organic dyes, FNDs have the advantage of lower toxicity, exceptional chemical stability, and better photostability. They can be surface functionalized by techniques similar to those used for other nanoparticles. They exhibit a variety of emission wavelengths from visible to near infrared, with narrow or broad bandwidths depending on their color centers. In addition, some color centers can detect changes in magnetic fields, electric fields, and temperature. In this article review, we will discuss the current trends in ...


Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi Jul 2018

Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Graphene is one of the emerging materials in the nanotechnology industry due to its potential applications in diverse areas. We report the fabrication of graphene nanosheets by spontaneous electrochemical reaction using solvated ion intercalation into graphite. The current literature focuses on the fabrication of graphene using lithium metal. Our procedure uses sodium metal, which results in a reduction of costs. Using various characterization techniques, we confirmed the fabrication of graphene nanosheets. We obtained an intensity ratio (ID/IG) of 0.32 using Raman spectroscopy, interlayer spacing of 0.39 nm and our XPS results indicate that our fabricated compound is ...


Printed Graphene Electrochemical Biosensors Fabricated By Inkjet Maskless Lithography For Rapid And Sensitive Detection Of Organophosphates, John A. Hondred, Joyce C. Breger, Nathan J. Alves, Scott A. Trammell, Scott A. Walper, Igor L. Medintz, Jonathan C. Claussen Mar 2018

Printed Graphene Electrochemical Biosensors Fabricated By Inkjet Maskless Lithography For Rapid And Sensitive Detection Of Organophosphates, John A. Hondred, Joyce C. Breger, Nathan J. Alves, Scott A. Trammell, Scott A. Walper, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Solution phase printing of graphene-based electrodes has recently become an attractive low-cost, scalable manufacturing technique to create in-field electrochemical biosensors. Here we report a graphene-based electrode developed via Inkjet Maskless Lithography (IML) for the direct and rapid monitoring of triple-O linked phosphonate organophosphates (OPs); these constitute the active compounds found in chemical warfare agents and pesticides that exhibit acute toxicity as well as long-term pollution to soils and waterways. The IML printed graphene electrode is nano/microstructured with a 1000 mW benchtop laser engraver and electrochemically deposited platinum nanoparticles (dia. ~25 nm) to improve its electrical conductivity (sheet resistance decreased ...


Actuation Of Chitosan-Aptamer Nanobrush Borders For Pathogen Sensing, Katherine D. Hills, Daniela Alves De Oliveira, Nicholas D. Cavallaro, Carmen L. Gomes, Eric S. Mclamore Jan 2018

Actuation Of Chitosan-Aptamer Nanobrush Borders For Pathogen Sensing, Katherine D. Hills, Daniela Alves De Oliveira, Nicholas D. Cavallaro, Carmen L. Gomes, Eric S. Mclamore

Mechanical Engineering Publications

We demonstrate a sensing mechanism for rapid detection of Listeria monocytogenes in food samples using the actuation of chitosan-aptamer nanobrush borders. The bio-inspired soft material and sensing strategy mimic natural symbiotic systems, where low levels of bacteria are selectively captured from complex matrices. To engineer this biomimetic system, we first develop reduced graphene oxide/nanoplatinum (rGO-nPt) electrodes, and characterize the fundamental electrochemical behavior in the presence and absence of chitosan nanobrushes during actuation (pH-stimulated osmotic swelling). We then characterize the electrochemical behavior of the nanobrush when receptors (antibodies or DNA aptamers) are conjugated to the surface. Finally, we test various ...


Post Hoc Support Vector Machine Learning For Impedimetric Biosensors Based On Weak Protein-Ligand Interactions, Yue Rong, Andrea Padron, Kyle Hagerty, Natalie Nelson, Song Chi, Nemat O. Keyhani, Joe Katz, Shoumen P. A. Datta, Carmen Gomes, Eric S. Mclamore Jan 2018

Post Hoc Support Vector Machine Learning For Impedimetric Biosensors Based On Weak Protein-Ligand Interactions, Yue Rong, Andrea Padron, Kyle Hagerty, Natalie Nelson, Song Chi, Nemat O. Keyhani, Joe Katz, Shoumen P. A. Datta, Carmen Gomes, Eric S. Mclamore

Mechanical Engineering Publications

Impedimetric biosensors for measuring small molecules based on weak/transient interactions between bioreceptor and target analyte are a challenge for detection electronics, particularly in field studies or in analysis of complex matrices. Protein-ligand binding sensors have enormous potential for biosensing, but accuracy in complex solutions is a major challenge. There is a need for simple post hoc analytical tools that are not computationally expensive, yet provide near real time feedback on data derived from impedance spectra. Here, we show use of a simple, open source support vector machine learning algorithm for analyzing impedimetric data in lieu of using equivalent circuit ...


Flexible Thermoelectric Generators With Inkjet-Printed Bismuth Telluride Nanowires And Liquid Metal Contacts, Bolin Chen, Matthew Kruse, Biao Xu, Ravi Tutika, Wei Zheng, Michael D. Bartlett, Yue Wu, Jonathan C. Claussen Jan 2018

Flexible Thermoelectric Generators With Inkjet-Printed Bismuth Telluride Nanowires And Liquid Metal Contacts, Bolin Chen, Matthew Kruse, Biao Xu, Ravi Tutika, Wei Zheng, Michael D. Bartlett, Yue Wu, Jonathan C. Claussen

Mechanical Engineering Publications

Solution phase printing of nanomaterials is becoming increasingly important for the creation of scalable flexible electronics including those associated with biomedical and energy harvesting applications. However, the use of solution-phase printed thermoelectric energy generators (TEGs) has been minimally explored. Herein we report a highly flexible inkjet-printed TEG. Bismuth telluride (Bi2Te3) and bismuth antimony telluride (Bi0.5Sb1.5Te3) nanowires (NWs) are inkjet printed onto polyimide to form n-type and p-type legs for the TEGs. A post-print thermal annealing process is used to increase the thermoelectric performance of the printed NWs while eutectic gallium-indium (EGaIn) liquid metal contacts electrically connect the TEG ...


Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen Jan 2018

Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen

Mechanical Engineering Publications

Vertically aligned carbon nanotube array (VANTA) coatings have recently garnered much attention due in part to their unique material properties including light absorption, chemical inertness, and electrical conductivity. Herein we report the first use of VANTAs grown via chemical vapor deposition in a 2D interdigitated electrode (IDE) footprint with a high height-to-width aspect ratio (3:1 or 75:25 µm). The VANTA-IDE is functionalized with an antibody (Ab) specific to the human cancerous inhibitor PP2A (CIP2A)—a salivary oncoprotein that is associated with a variety of malignancies such as oral, breast, and multiple myeloma cancers. The resultant immunosensor is capable ...


Fluid‐Induced Alignment Of Carbon Nanofibers In Polymer Fibers, Mingchang Lu, Farrokh Sharifi, Nicole N. Hashemi, Reza Montazami Jul 2017

Fluid‐Induced Alignment Of Carbon Nanofibers In Polymer Fibers, Mingchang Lu, Farrokh Sharifi, Nicole N. Hashemi, Reza Montazami

Mechanical Engineering Publications

Carbon nanofiber/polycaprolactone (CNF/PCL) composite fibers are fabricated using a microfluidic approach. The fibers are made with different content levels of CNFs and flow rate ratios between the core and sheath fluids. The electrical conductivity and tensile properties of these fibers are then investigated. It is found that at a CNF concentration of 3 wt%, the electrical conductivity of the composite fiber significantly increases to 1.11 S m−1. The yield strength, Young's modulus, and ultimate strength of the 3 wt% CNF increase relative to the pure PCL by factors of 1.72, 2.88, and 1 ...


Enhanced Enzymatic Activity From Phosphotriesterase Trimer Gold Nanoparticle Bioconjugates For Pesticide Detection, John A. Hondred, Joyce C. Breger, Nate T. Garland, Eunkeu Oh, Kimihiro Susumu, Scott A. Walper, Igor L. Medintz, Jonathan C. Claussen Jan 2017

Enhanced Enzymatic Activity From Phosphotriesterase Trimer Gold Nanoparticle Bioconjugates For Pesticide Detection, John A. Hondred, Joyce C. Breger, Nate T. Garland, Eunkeu Oh, Kimihiro Susumu, Scott A. Walper, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

The rapid detection of organophosphates (OPs), a class of strong neurotoxins, is critically important for monitoring acute insecticide exposure and potential chemical warfare agent use. Herein, we improve the enzymatic activity of a phosphotriesterase trimer (PTE3), an enzyme that selectively recognizes OPs directly, by conjugation with distinctly sized (i.e., 5, 10, and 20 nm diameter) gold nanoparticles (AuNPs). The number of enzymes immobilized on the AuNP was controlled by conjugating increasing molar ratios of PTE3 onto the AuNP surface via metal affinity coordination. This occurs between the PTE3-His6 termini and the AuNP-displayed Ni2+-nitrilotriacetic acid end groups and was ...


Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen Jan 2016

Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts ...


Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen Jan 2016

Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts ...


Fiber Based Approaches As Medicine Delivery Systems, Farrokh Sharifi, Avinash C. Sooriyarachchi, Hayriye Altural, Reza Montazami, Marissa Nichole Rylander, Nicole Nastaran Hashemi Jan 2016

Fiber Based Approaches As Medicine Delivery Systems, Farrokh Sharifi, Avinash C. Sooriyarachchi, Hayriye Altural, Reza Montazami, Marissa Nichole Rylander, Nicole Nastaran Hashemi

Mechanical Engineering Publications

The goal of drug delivery is to ensure that therapeutic molecules reach the intended target organ or tissue, such that the effectiveness of the drug is maximized. The efficiency of a drug delivery system greatly depends on the choice of drug carrier. Recently, there has been growing interest in using micro- and nanofibers for this purpose. The reasons for this growing interest include these materials’ high surface area to volume ratios, ease of fabrication, high mechanical properties, and desirable drug release profile. Here, we review developments in using these materials made by the most prevalent methods of fiber fabrication: electrospinning ...


Increasing The Activity Of Immobilized Enzymes With Nanoparticle Conjugation, Shaowei Ding, Allison A. Cargill, Igor L. Medintz, Jonathan C. Claussen Aug 2015

Increasing The Activity Of Immobilized Enzymes With Nanoparticle Conjugation, Shaowei Ding, Allison A. Cargill, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

The efficiency and selectivity of enzymatic catalysis is useful to a plethora of industrial and manufacturing processes. Many of these processes require the immobilization of enzymes onto surfaces, which has traditionally reduced enzyme activity. However, recent research has shown that the integration of nanoparticles into enzyme carrier schemes has maintained or even enhanced immobilized enzyme performance. The nanoparticle size and surface chemistry as well as the orientation and density of immobilized enzymes all contribute to the enhanced performance of enzyme–nanoparticle conjugates. These improvements are noted in specific nanoparticles including those comprising carbon (e.g., graphene and carbon nanotubes), metal ...


Utilizing Wide Band Gap, High Dielectric Constant Nanoparticles As Additives In Organic Solar Cells, Ryan S. Gebhardt, Pengfei Du, Akshit Peer, Mitch Rock, Michael R. Kessler, Rana Biswas, Baskar Ganapathysubramanian, Sumit Chaudhary Jan 2015

Utilizing Wide Band Gap, High Dielectric Constant Nanoparticles As Additives In Organic Solar Cells, Ryan S. Gebhardt, Pengfei Du, Akshit Peer, Mitch Rock, Michael R. Kessler, Rana Biswas, Baskar Ganapathysubramanian, Sumit Chaudhary

Mechanical Engineering Publications

We experimentally and theoretically investigate the effects of utilizing BaTiO3 nanoparticles as additives in polythiophene/fullerene solar cells. BaTiO3 nanoparticles were chosen because of their multifaceted potential for increasing exciton dissociation (due to their high dielectric constant) and light scattering. To achieve stable suspensions for device fabrication, the nanoparticles were functionalized with organic ligands. Solar cells fabricated in air showed ∼40% enhancement in the photocurrent primarily due to string-like aggregates of functionalized BaTiO3 particles that increase light absorption without hindering charge collection. Solar cells fabricated in an inert atmosphere yielded overall more efficient devices, but the string-like aggregates were absent ...


High Aspect Ratio Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2o2 Decomposition, Kevin Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen Jan 2015

High Aspect Ratio Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2o2 Decomposition, Kevin Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen

Mechanical Engineering Publications

The utility of unmanned micro underwater vehicles (MUVs) is paramount for exploring confined spaces, but their spatial agility is often impaired when maneuvers require burst-propulsion. Herein we develop high-aspect ratio (150:1), multiwalled carbon nanotube microarray membranes (CNT-MMs) for propulsive, MUV thrust generation by the decomposition of hydrogen peroxide (H2O2). The CNT-MMs are grown via chemical vapor deposition with diamond shaped pores (nominal diagonal dimensions of 4.5 × 9.0 μm) and subsequently decorated with urchin-like, platinum (Pt) nanoparticles via a facile, electroless, chemical deposition process. The Pt-CNT-MMs display robust, high catalytic ability with an effective activation ...


Multi-Pixel Photon Counters For Optofluidic Characterization Of Particles And Microalgae, Pouya Asrar, Marta Sucur, Nicole N. Hashemi Jan 2015

Multi-Pixel Photon Counters For Optofluidic Characterization Of Particles And Microalgae, Pouya Asrar, Marta Sucur, Nicole N. Hashemi

Mechanical Engineering Publications

We have developed an optofluidic biosensor to study microscale particles and different species of microalgae. The system is comprised of a microchannel with a set of chevron-shaped grooves. The chevrons allows for hydrodynamic focusing of the core stream in the center using a sheath fluid. The device is equipped with a new generation of highly sensitive photodetectors, multi-pixel photon counter (MPPC), with high gain values and an extremely small footprint. Two different sizes of high intensity fluorescent microspheres and three different species of algae (Chlamydomonas reinhardtii strain 21 gr, Chlamydomonas suppressor, and Chlorella sorokiniana) were studied. The forward scattering emissions ...


Achieving Bicontinuous Microemulsion Like Morphologies In Organic Photovoltaics, Dylan Kipp, Olga Wodo, Baskar Ganapathysubramanian, Venkat Ganesan Jan 2015

Achieving Bicontinuous Microemulsion Like Morphologies In Organic Photovoltaics, Dylan Kipp, Olga Wodo, Baskar Ganapathysubramanian, Venkat Ganesan

Mechanical Engineering Publications

It is believed that the optimal morphology of an organic solar cell may be characterized by cocontinuous, interpenetrating donor and acceptor domains with nanoscale dimensions and high interfacial areas. One well-known equilibrium morphology that fits these characteristics is the bicontinuous microemulsion achieved by the addition of block copolymer compatibilizers to flexible polymer–polymer blends. However, there does not exist design rules for using block copolymer compatibilizers to produce bicontinuous microemulsion morphologies from the conjugated polymer/fullerene mixtures typically used to form the active layer of organic solar cells. Motivated by these considerations, we use single chain in mean field simulations ...


Electrode Materials, Thermal Annealing Sequences, And Lateral/Vertical Phase Separation Of Polymer Solar Cells From Multiscale Molecular Simulations, Cheng-Kuang Lee, Olga Wodo, Baskar Ganapathysubramanian, Chun-Wei Pao Jan 2014

Electrode Materials, Thermal Annealing Sequences, And Lateral/Vertical Phase Separation Of Polymer Solar Cells From Multiscale Molecular Simulations, Cheng-Kuang Lee, Olga Wodo, Baskar Ganapathysubramanian, Chun-Wei Pao

Mechanical Engineering Publications

The nanomorphologies of the bulk heterojunction (BHJ) layer of polymer solar cells are extremely sensitive to the electrode materials and thermal annealing conditions. In this work, the correlations of electrode materials, thermal annealing sequences, and resultant BHJ nanomorphological details of P3HT:PCBM BHJ polymer solar cell are studied by a series of large-scale, coarse-grained (CG) molecular simulations of system comprised of PEDOT:PSS/P3HT:PCBM/Al layers. Simulations are performed for various configurations of electrode materials as well as processing temperature. The complex CG molecular data are characterized using a novel extension of our graph-based framework to quantify morphology and ...