This paper reports a comparative study of InAs/GaAs quantum dots (QDs) heterostructures with vertically aligned strain-coupled uncapped and capped buried dots, epitaxially grown by solid-state MBE. Here an in-situ method is used to optimize the band alignment among the coupled QD heterostructures. In this work, the stable uncapped QDs are grown with reduced surface energy using the self-assembly growth technique called Stranski Krastanov (SK) QDs. During growth we reduced the Indium flux to the top uncapped QDs layer referred to as Surface QDs (SQDs), keeping a constant overgrowth percentage (2.7 ML) for capped QDs known as buried QDs (BQDs). Up to 2 ML SQD, two distinguished energy states for BQD and SQD are observed, showing a gradual blue-shift as the InAs content reduces from 2.2 to 2 ML. As we get into the regime of 1.6ML, the energy states of SQD are in resonating condition with the BQDs. This resonance enhances the electronic interaction between the coupled dot layers. The corresponding photoluminescence response depicts the wave function overlapping surface and buried dots. In addition, AFM images show a homogeneous distribution in size and shape of the SQDs in this regime. Strain analysis of the heterostructure is performed by Raman spectroscopy and HRXRD measurement. The heterostructure with 1.6 ML coverage would promise a sensor based on SK-QDs with high efficiency due to inter-dot carrier communication. Here the underneath capped QD supplies surplus carriers act like a reservoir and the surface QD layers act as a primary receptor.
{"title":"In-situ tailoring of band alignment between strain-coupled surface and buried InAs/GaAs quantum dots for sensor applications","authors":"M. Mantri, D. Panda, R. Saha, S. Chakrabarti","doi":"10.1117/12.2677942","DOIUrl":"https://doi.org/10.1117/12.2677942","url":null,"abstract":"This paper reports a comparative study of InAs/GaAs quantum dots (QDs) heterostructures with vertically aligned strain-coupled uncapped and capped buried dots, epitaxially grown by solid-state MBE. Here an in-situ method is used to optimize the band alignment among the coupled QD heterostructures. In this work, the stable uncapped QDs are grown with reduced surface energy using the self-assembly growth technique called Stranski Krastanov (SK) QDs. During growth we reduced the Indium flux to the top uncapped QDs layer referred to as Surface QDs (SQDs), keeping a constant overgrowth percentage (2.7 ML) for capped QDs known as buried QDs (BQDs). Up to 2 ML SQD, two distinguished energy states for BQD and SQD are observed, showing a gradual blue-shift as the InAs content reduces from 2.2 to 2 ML. As we get into the regime of 1.6ML, the energy states of SQD are in resonating condition with the BQDs. This resonance enhances the electronic interaction between the coupled dot layers. The corresponding photoluminescence response depicts the wave function overlapping surface and buried dots. In addition, AFM images show a homogeneous distribution in size and shape of the SQDs in this regime. Strain analysis of the heterostructure is performed by Raman spectroscopy and HRXRD measurement. The heterostructure with 1.6 ML coverage would promise a sensor based on SK-QDs with high efficiency due to inter-dot carrier communication. Here the underneath capped QD supplies surplus carriers act like a reservoir and the surface QD layers act as a primary receptor.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"40 1","pages":"126510A - 126510A-10"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80599569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kewen Xiao, Satyamev Jha, M. Bhattacharya, L. Deych
In traditional cavity optomechanical models, a coupling between the cavity field and mechanical degrees of freedom is a result of dependence of the frequency or the life-time of a cavity mode on mechanical variables. However, optical cavities with degenerate modes may exhibit a different type of optomechanical coupling, which originates from the spatial reconfiguration of the cavity field caused by mechanical motion. Such coupling can, for instance, arise in the case of whispering-gallery-modes in spherical resonators interacting with a polarizable dipole. Here we introduce a model with this previously unexplored type of optomechanical coupling, and as a first step toward understanding the properties of this model we study its classical dynamics in the absence of dissipation and an external pump. We show that the dynamical properties of such a model are characterized by a bifurcation manifested by a loss of stability of a simple equilibrium and a transition to a more complex nonlinear dynamics.
{"title":"A new optomechanical interaction and a model with non-trivial classical dynamics","authors":"Kewen Xiao, Satyamev Jha, M. Bhattacharya, L. Deych","doi":"10.1117/12.2676579","DOIUrl":"https://doi.org/10.1117/12.2676579","url":null,"abstract":"In traditional cavity optomechanical models, a coupling between the cavity field and mechanical degrees of freedom is a result of dependence of the frequency or the life-time of a cavity mode on mechanical variables. However, optical cavities with degenerate modes may exhibit a different type of optomechanical coupling, which originates from the spatial reconfiguration of the cavity field caused by mechanical motion. Such coupling can, for instance, arise in the case of whispering-gallery-modes in spherical resonators interacting with a polarizable dipole. Here we introduce a model with this previously unexplored type of optomechanical coupling, and as a first step toward understanding the properties of this model we study its classical dynamics in the absence of dissipation and an external pump. We show that the dynamical properties of such a model are characterized by a bifurcation manifested by a loss of stability of a simple equilibrium and a transition to a more complex nonlinear dynamics.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"31 1","pages":"126490O - 126490O-24"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76146138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tungsten oxide (WO3), which is also known as tungsten trioxide and wide band gap semiconductor material has drawn enormous attention among researchers due to its fascinating properties. Using facile one step hydrothermal method, the synthesis and characterizations of highly crystalline 1D nanorod of WO3 are presented in this paper with large scale production of the material. Several characterization techniques, such as transmission electron microscopy (TEM), field emission gun-scanning electron microscopy (FEG-SEM), X-ray diffraction (XRD), UV-vis spectroscopy have been employed to check the crystallinity, surface morphology, shape, and band gap of the nanomaterial. The XRD data confirms about the highly crystalline hexagonal phase of WO3, which agrees well with the JCPDS card no – 01-085- 2459. Nanorod like morphology can be seen in the low-resolution TEM image. In the HRTEM image, the highly crystalline nature of the material is clearly visible and the obtained interplanar spacing is 0.38 nm which matches with the interplanar spacing of (002) plane. The FEG-SEM image shows the 1D nanorod morphology of the synthesized material. The diameters of the nanorods are in the range of 50-300 nm. The Fourier transform infrared spectroscopy (FTIR) revels the structural information about the synthesized material. The broad peak around 805 cm-1 is attributed to the W-O-W bond stretching vibration. Two other peaks appeared at 1405 and 1628 cm-1 are representing the vibration mode of W-OH bond. We have also studied the UV-vis absorption spectroscopy of the WO3 nanorod to investigate the light absorption property of the material. The band gap obtained from the Tauc plot is 3.16 eV, indicates the wide and direct band gap formation of WO3 nanorod. The synthesized material is suitable for various applications, such as gas sensing, UV photodetector, supercapacitor, and photocatalyst.
{"title":"Growth of highly crystalline WO3 nanorod using a facile hydrothermal synthesis","authors":"A. Mandal, K. Das Gupta, S. Chakrabarti","doi":"10.1117/12.2676813","DOIUrl":"https://doi.org/10.1117/12.2676813","url":null,"abstract":"Tungsten oxide (WO3), which is also known as tungsten trioxide and wide band gap semiconductor material has drawn enormous attention among researchers due to its fascinating properties. Using facile one step hydrothermal method, the synthesis and characterizations of highly crystalline 1D nanorod of WO3 are presented in this paper with large scale production of the material. Several characterization techniques, such as transmission electron microscopy (TEM), field emission gun-scanning electron microscopy (FEG-SEM), X-ray diffraction (XRD), UV-vis spectroscopy have been employed to check the crystallinity, surface morphology, shape, and band gap of the nanomaterial. The XRD data confirms about the highly crystalline hexagonal phase of WO3, which agrees well with the JCPDS card no – 01-085- 2459. Nanorod like morphology can be seen in the low-resolution TEM image. In the HRTEM image, the highly crystalline nature of the material is clearly visible and the obtained interplanar spacing is 0.38 nm which matches with the interplanar spacing of (002) plane. The FEG-SEM image shows the 1D nanorod morphology of the synthesized material. The diameters of the nanorods are in the range of 50-300 nm. The Fourier transform infrared spectroscopy (FTIR) revels the structural information about the synthesized material. The broad peak around 805 cm-1 is attributed to the W-O-W bond stretching vibration. Two other peaks appeared at 1405 and 1628 cm-1 are representing the vibration mode of W-OH bond. We have also studied the UV-vis absorption spectroscopy of the WO3 nanorod to investigate the light absorption property of the material. The band gap obtained from the Tauc plot is 3.16 eV, indicates the wide and direct band gap formation of WO3 nanorod. The synthesized material is suitable for various applications, such as gas sensing, UV photodetector, supercapacitor, and photocatalyst.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"40 1","pages":"1265003 - 1265003-7"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81255490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mantri, D. Panda, Ravindra Kumar, Samishta Choudhary, S. Chakrabarti
In the past decade, surface quantum dots (SQDs) have been thoroughly investigated for sensing applications. The SQDs suffer from the limitations of non-uniformity dot distribution and weak oscillator strength, which affect their response to ambient contaminants. We have achieved uniformity by coupling buried quantum dots (BQDs) with SQDs. Moreover, BQDs provide additional carriers to SQDs for enhancing sensitivity. In this study, we have theoretically investigated the impact of varying the capping material of BQDs on their strain and optical properties. Investigations have been carried out with three samples having different capping materials as GaAs (sample A1), InGaAs (sample A2), and InAlGaAs (sample A3). A decreasing trend in the magnitude of hydrostatic strain and an increasing trend in biaxial strain inside the BQD from samples A1-A3 is observed. With a decrease in hydrostatic strain, the conduction band eigenstate lowers towards the band edge resulting in a lowering bandgap. With an increase in biaxial strain, the bandgap lowers due to the heavy hole (HH) and light hole (LH) band splitting. The lowering of the bandgap enhances the luminescence of BQD in sample A3. The computed photo-luminescence (PL) emission wavelength is found to be 1547 nm, 1558 nm, and 1568 nm for GaAs, InAlGaAs, and InGaAs capping respectively. The lowering in the bandgap of BQD leads to band alignment between SQD and BQDs, which may improve the carrier communication between these layers and become a promising candidate for better carrier reservoirs for SQDs in sensor applications.
{"title":"A theoretical study on strain and optical property of InAs SK quantum dot with varying capping in SK-SML coupled surface quantum dot heterostructure","authors":"M. Mantri, D. Panda, Ravindra Kumar, Samishta Choudhary, S. Chakrabarti","doi":"10.1117/12.2677964","DOIUrl":"https://doi.org/10.1117/12.2677964","url":null,"abstract":"In the past decade, surface quantum dots (SQDs) have been thoroughly investigated for sensing applications. The SQDs suffer from the limitations of non-uniformity dot distribution and weak oscillator strength, which affect their response to ambient contaminants. We have achieved uniformity by coupling buried quantum dots (BQDs) with SQDs. Moreover, BQDs provide additional carriers to SQDs for enhancing sensitivity. In this study, we have theoretically investigated the impact of varying the capping material of BQDs on their strain and optical properties. Investigations have been carried out with three samples having different capping materials as GaAs (sample A1), InGaAs (sample A2), and InAlGaAs (sample A3). A decreasing trend in the magnitude of hydrostatic strain and an increasing trend in biaxial strain inside the BQD from samples A1-A3 is observed. With a decrease in hydrostatic strain, the conduction band eigenstate lowers towards the band edge resulting in a lowering bandgap. With an increase in biaxial strain, the bandgap lowers due to the heavy hole (HH) and light hole (LH) band splitting. The lowering of the bandgap enhances the luminescence of BQD in sample A3. The computed photo-luminescence (PL) emission wavelength is found to be 1547 nm, 1558 nm, and 1568 nm for GaAs, InAlGaAs, and InGaAs capping respectively. The lowering in the bandgap of BQD leads to band alignment between SQD and BQDs, which may improve the carrier communication between these layers and become a promising candidate for better carrier reservoirs for SQDs in sensor applications.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"65 1","pages":"126510B - 126510B-6"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83447487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katelyn Lee, Hiro Ishikawa, Celina Jiang, B. Campbell, Elise Stuman, Jiayu Hu, Veronica Gomez, Wallace Marshall, Linda Z. Shi
Single-cell green algae (C. Reinhardtii) is a key model organism to study ciliogenesis. Cilia have important roles in sensory signaling pathways and in clearing the airways of mucus and dirt in multiple systems of the human body. As cilia are found on most eukaryotic cells, defects in ciliogenesis result in many symptoms and disorders. We are testing the hypothesis that when a flagellum is removed, the long flagellum shrinks because it is competing with the shorter regrowing flagellum. We used a 780-nm 200-fs laser to perform laser ablation to amputate one of two flagella on wildtype and mutant algae. Fla3 and Fla10 mutants were altered to inhibit the KAP kinesin motor that drives the intraflagellar transport (IFT) pathway. Impaired IFT pathways would demonstrate a lag in response to flagellar length equalization and a reduced disassembly rate. Quantified images following the long flagellum for 20 min post-ablation demonstrate a delayed disassembly rate in the Fla3 mutant compared to wildtype; Fla10 was inconclusive. Therefore, it was concluded that the proper function of KAP motor protein serves a significant role in length control of cilia. In the future, we will compare the assembly rates of flagellar regrowth for the wildtype and mutants.
{"title":"Tracking of C. Reinhardtii flagellar disassembly following femtosecond laser ablation","authors":"Katelyn Lee, Hiro Ishikawa, Celina Jiang, B. Campbell, Elise Stuman, Jiayu Hu, Veronica Gomez, Wallace Marshall, Linda Z. Shi","doi":"10.1117/12.2677805","DOIUrl":"https://doi.org/10.1117/12.2677805","url":null,"abstract":"Single-cell green algae (C. Reinhardtii) is a key model organism to study ciliogenesis. Cilia have important roles in sensory signaling pathways and in clearing the airways of mucus and dirt in multiple systems of the human body. As cilia are found on most eukaryotic cells, defects in ciliogenesis result in many symptoms and disorders. We are testing the hypothesis that when a flagellum is removed, the long flagellum shrinks because it is competing with the shorter regrowing flagellum. We used a 780-nm 200-fs laser to perform laser ablation to amputate one of two flagella on wildtype and mutant algae. Fla3 and Fla10 mutants were altered to inhibit the KAP kinesin motor that drives the intraflagellar transport (IFT) pathway. Impaired IFT pathways would demonstrate a lag in response to flagellar length equalization and a reduced disassembly rate. Quantified images following the long flagellum for 20 min post-ablation demonstrate a delayed disassembly rate in the Fla3 mutant compared to wildtype; Fla10 was inconclusive. Therefore, it was concluded that the proper function of KAP motor protein serves a significant role in length control of cilia. In the future, we will compare the assembly rates of flagellar regrowth for the wildtype and mutants.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"29 6 Suppl 19 1","pages":"126490T - 126490T-3"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77859101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrogen has garnered widespread attention as a pivotal indicator for future sustainable development. Current research aims to utilize clean energy for hydrogen production, thereby minimizing the generation of by-products such as hydrocarbons. Two-dimensional molybdenum disulfide (2D-MoS2) has demonstrated outstanding photoelectrocatalytic (PEC) performance and shows promise as a material for photocatalytic (PC) hydrogen evolution (HER). However, its atomic-scale thickness limits light absorption. Therefore, the introduction of plasmonic metal nanoparticles to enhance light-matter interactions through the plasmonic resonance effect can substantially improve the overall catalytic efficiency. Conventional single-element noble metal nanoparticles exhibit relatively poor catalytic effects, while multi-element alloys have emerged as excellent catalysts due to their high entropy effect. In this study, we designed a heterostructure (SiNW/MoS2/HEANP) by combining silicon nanowires, molybdenum disulfide, and a novel high-entropy alloy nanoparticle to demonstrate outstanding photocatalytic hydrogen evolution performance. The silicon nanowire structure, exploiting light-trapping effects, exhibited high anti-reflection properties, achieving over 97% absorption of visible light and providing abundant reaction sites. Moreover, the mixed-phase structure of 1T and 2H MoS2, synthesized via thermal pyrolysis, contributed to the enhanced HER performance of the material. The HEA(AgAlCuNiTi) nanoparticles, synthesized through sputtering and annealing, exhibited a significant synergistic effect with MoS2 through its decent plasmonic resonance and excellent HER activity, resulting in a substantially improved overall catalytic efficiency. The SiNW/MoS2/HEANP heterostructure demonstrated a remarkable hydrogen generation rate of 475.5 mmol g-1 h-1. This study presents a strategy for utilizing HEAs as promising materials for photocatalytic hydrogen evolution with tremendous potential.
{"title":"Novel high entropy alloy (AgAlCuNiTi) hybridized MoS2/Si nanowires heterostructure with plasmonic enhanced photocatalytic activity","authors":"Yu‐Hsuan Cheng, T. Yen","doi":"10.1117/12.2676326","DOIUrl":"https://doi.org/10.1117/12.2676326","url":null,"abstract":"Hydrogen has garnered widespread attention as a pivotal indicator for future sustainable development. Current research aims to utilize clean energy for hydrogen production, thereby minimizing the generation of by-products such as hydrocarbons. Two-dimensional molybdenum disulfide (2D-MoS2) has demonstrated outstanding photoelectrocatalytic (PEC) performance and shows promise as a material for photocatalytic (PC) hydrogen evolution (HER). However, its atomic-scale thickness limits light absorption. Therefore, the introduction of plasmonic metal nanoparticles to enhance light-matter interactions through the plasmonic resonance effect can substantially improve the overall catalytic efficiency. Conventional single-element noble metal nanoparticles exhibit relatively poor catalytic effects, while multi-element alloys have emerged as excellent catalysts due to their high entropy effect. In this study, we designed a heterostructure (SiNW/MoS2/HEANP) by combining silicon nanowires, molybdenum disulfide, and a novel high-entropy alloy nanoparticle to demonstrate outstanding photocatalytic hydrogen evolution performance. The silicon nanowire structure, exploiting light-trapping effects, exhibited high anti-reflection properties, achieving over 97% absorption of visible light and providing abundant reaction sites. Moreover, the mixed-phase structure of 1T and 2H MoS2, synthesized via thermal pyrolysis, contributed to the enhanced HER performance of the material. The HEA(AgAlCuNiTi) nanoparticles, synthesized through sputtering and annealing, exhibited a significant synergistic effect with MoS2 through its decent plasmonic resonance and excellent HER activity, resulting in a substantially improved overall catalytic efficiency. The SiNW/MoS2/HEANP heterostructure demonstrated a remarkable hydrogen generation rate of 475.5 mmol g-1 h-1. This study presents a strategy for utilizing HEAs as promising materials for photocatalytic hydrogen evolution with tremendous potential.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"52 1","pages":"126480C - 126480C-9"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74255349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sophia Barber, Sarah Chen, Veronica Gomez, Chengbiao Wu, Linda Shi
Axonal degeneration is a key component of neurodegenerative diseases such as Huntington’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS). (NAm), an NAD+ precursor, has long since been implicated in axonal protection and reduction of degeneration. On the other hand, hydrogen peroxide (H2O2) has been implicated in oxidative stress and axonal degeneration. The effects of laser-induced axonal damage in wild-type (WT) and Huntington’s disease(HD) mouse dorsal root ganglion neurons (DRGs) treated with NAm or H2O2 were investigated and the cell body width, axon width, axonal strength, and axon shrinkage post laser-induced injury were measured. We found that HD mouse DRGs have increased strength against laser damage compared to wild-type DRGs. We additionally found that treatment with NAm reduces the neuronal strength against laser damage in both WT and HD DRGs. Interestingly, when comparing HD DRGs treated with H2O2 and WT DRGs treated with H2O2, we found that treatment with H2O2 reduced the time required for the RoboLase laser system to cut through HD DRGs. We additionally found that both NAm and H2O2 treatments resulted in morphological changes in both WT and HD DRG cell bodies, respectively. We did not find any difference in shrinkage across the models. Ultimately, our results suggest that H2O2 at the same concentration may have less damaging effects on WT neurons than previously expected. Our results additionally indicate that higher concentrations of NAm, previously deemed to be safe, may have a neurotoxic effect rather than an axonal protective effect on HD and WT DRGs.
{"title":"Effects of H2O2 and high doses of nicotinamide on laser-induced neuronal degeneration in mouse model of Huntington’s disease","authors":"Sophia Barber, Sarah Chen, Veronica Gomez, Chengbiao Wu, Linda Shi","doi":"10.1117/12.2677626","DOIUrl":"https://doi.org/10.1117/12.2677626","url":null,"abstract":"Axonal degeneration is a key component of neurodegenerative diseases such as Huntington’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS). (NAm), an NAD+ precursor, has long since been implicated in axonal protection and reduction of degeneration. On the other hand, hydrogen peroxide (H2O2) has been implicated in oxidative stress and axonal degeneration. The effects of laser-induced axonal damage in wild-type (WT) and Huntington’s disease(HD) mouse dorsal root ganglion neurons (DRGs) treated with NAm or H2O2 were investigated and the cell body width, axon width, axonal strength, and axon shrinkage post laser-induced injury were measured. We found that HD mouse DRGs have increased strength against laser damage compared to wild-type DRGs. We additionally found that treatment with NAm reduces the neuronal strength against laser damage in both WT and HD DRGs. Interestingly, when comparing HD DRGs treated with H2O2 and WT DRGs treated with H2O2, we found that treatment with H2O2 reduced the time required for the RoboLase laser system to cut through HD DRGs. We additionally found that both NAm and H2O2 treatments resulted in morphological changes in both WT and HD DRG cell bodies, respectively. We did not find any difference in shrinkage across the models. Ultimately, our results suggest that H2O2 at the same concentration may have less damaging effects on WT neurons than previously expected. Our results additionally indicate that higher concentrations of NAm, previously deemed to be safe, may have a neurotoxic effect rather than an axonal protective effect on HD and WT DRGs.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"229 1","pages":"126490V - 126490V-12"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89210698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carla N. Labastida, J. P. Cuanalo, Irving Gazga, Rubén Ramos, S. Mansurova, N. Korneev
In this work, we have developed a refractive index change sensing system utilizing localized surface plasmon resonance (LSPR) transduction, combined with a position-sensitive photodetector (PSPD). As the transducers, we utilized gold nano-islands formed through thermal annealing of an Au film with a nominal thickness of 13 nm. The LSPR was excited by evanescent wave in an attenuated total reflectance configuration. Refractive index changes result in modifications across the angular spectrum of LSPR, giving rise to variations in the differential signal detected between the two quadrants of the photodetector. We determined the refractive index resolution of our sensing system at different wavelengths and performed a comparative analysis with traditional surface plasmon resonance (SPR) transducers and available literature data. While LSPR transducers demonstrate a lower refractive index resolution (RIR) compared to SPR, the approach presented in this work stands out when compared to other LSPR sensing methods. Notably, at a wavelength of 785 nm, it achieves a remarkable RIR of 1.4 × 10−6 RIU.
{"title":"Position-sensitive photodetector for plasmonic detection in a random metasurface","authors":"Carla N. Labastida, J. P. Cuanalo, Irving Gazga, Rubén Ramos, S. Mansurova, N. Korneev","doi":"10.1117/12.2677359","DOIUrl":"https://doi.org/10.1117/12.2677359","url":null,"abstract":"In this work, we have developed a refractive index change sensing system utilizing localized surface plasmon resonance (LSPR) transduction, combined with a position-sensitive photodetector (PSPD). As the transducers, we utilized gold nano-islands formed through thermal annealing of an Au film with a nominal thickness of 13 nm. The LSPR was excited by evanescent wave in an attenuated total reflectance configuration. Refractive index changes result in modifications across the angular spectrum of LSPR, giving rise to variations in the differential signal detected between the two quadrants of the photodetector. We determined the refractive index resolution of our sensing system at different wavelengths and performed a comparative analysis with traditional surface plasmon resonance (SPR) transducers and available literature data. While LSPR transducers demonstrate a lower refractive index resolution (RIR) compared to SPR, the approach presented in this work stands out when compared to other LSPR sensing methods. Notably, at a wavelength of 785 nm, it achieves a remarkable RIR of 1.4 × 10−6 RIU.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"2 2 1","pages":"126480G - 126480G-7"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90455361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kyle E. Chaney, Chase Grochett, Benjamin Coers, Omner Cervantes, Cooper D. Bond, J. J. Sheridan, D. Smalley
In this work we report an improved platform for testing and comparing particles for use in optical trap displays. We constructed seven prototypes, and deployed them to five different locations where they were successfully used to perform comparative optical particle trap tests. This improved rig makes it possible to expand optical trap display research by a decentralized group of citizen scientists.
{"title":"Test rig for comparison of particle types for 3D optical trap displays","authors":"Kyle E. Chaney, Chase Grochett, Benjamin Coers, Omner Cervantes, Cooper D. Bond, J. J. Sheridan, D. Smalley","doi":"10.1117/12.2675509","DOIUrl":"https://doi.org/10.1117/12.2675509","url":null,"abstract":"In this work we report an improved platform for testing and comparing particles for use in optical trap displays. We constructed seven prototypes, and deployed them to five different locations where they were successfully used to perform comparative optical particle trap tests. This improved rig makes it possible to expand optical trap display research by a decentralized group of citizen scientists.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"36 1","pages":"126490S - 126490S-4"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85306956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Vasantham, P. Garstecki, Ladislav Derzsi, Abhay Kotnala
Raman fingerprinting of leukemic cells has potential applications in diagnosis and in vitro chemosensitivity assessment. A biochemical map of the contents of leukemic cells can not only help distinguish cancer patients from healthy ones but also shed light on different subtypes of leukemia such as ALL, AML, etc. Certain important requirements need to be fulfilled to effectively measure the Raman map of a single leukemic cell. Firstly, since the leukemia cells are suspension cells, it is preferred to keep them in a free solution rather than attached to a fixed surface during signal acquisition. Secondly, the cells need to be immobilized for several seconds, for the acquisition of the weak Raman signal even when using stimulated Raman Spectroscopy (SRS) which provides relatively stronger Raman signal. Thus, a device capable of sequentially flowing, holding, and releasing individual leukemia cells in a robust, efficient and high-throughput manner is required. We present an optofluidic fiber tweezers device comprised of a novel combination of 3D hydrodynamic flow focusing and optical fiber in a microfluidic chip. By exploiting the interplay between the optical and hydrodynamic forces acting on the cell, we demonstrate rapid, efficient, sequential delivery and trapping of single leukemic cells in a flow cytometer format followed by SRS imaging of the trapped cell. The specific Raman vibration bands corresponding to the lipids, nucleic acids, and proteins in the trapped cells were analyzed to distinguish cancerous cells from healthy cells. Our device is also capable of isolating cells with unique Raman signatures for further processing using techniques like gene sequencing etc.
{"title":"Opto-hydrodynamic fiber tweezers for stimulated Raman imaging cytometry of leukemic cells","authors":"S. Vasantham, P. Garstecki, Ladislav Derzsi, Abhay Kotnala","doi":"10.1117/12.2677250","DOIUrl":"https://doi.org/10.1117/12.2677250","url":null,"abstract":"Raman fingerprinting of leukemic cells has potential applications in diagnosis and in vitro chemosensitivity assessment. A biochemical map of the contents of leukemic cells can not only help distinguish cancer patients from healthy ones but also shed light on different subtypes of leukemia such as ALL, AML, etc. Certain important requirements need to be fulfilled to effectively measure the Raman map of a single leukemic cell. Firstly, since the leukemia cells are suspension cells, it is preferred to keep them in a free solution rather than attached to a fixed surface during signal acquisition. Secondly, the cells need to be immobilized for several seconds, for the acquisition of the weak Raman signal even when using stimulated Raman Spectroscopy (SRS) which provides relatively stronger Raman signal. Thus, a device capable of sequentially flowing, holding, and releasing individual leukemia cells in a robust, efficient and high-throughput manner is required. We present an optofluidic fiber tweezers device comprised of a novel combination of 3D hydrodynamic flow focusing and optical fiber in a microfluidic chip. By exploiting the interplay between the optical and hydrodynamic forces acting on the cell, we demonstrate rapid, efficient, sequential delivery and trapping of single leukemic cells in a flow cytometer format followed by SRS imaging of the trapped cell. The specific Raman vibration bands corresponding to the lipids, nucleic acids, and proteins in the trapped cells were analyzed to distinguish cancerous cells from healthy cells. Our device is also capable of isolating cells with unique Raman signatures for further processing using techniques like gene sequencing etc.","PeriodicalId":13820,"journal":{"name":"International Conference on Nanoscience, Engineering and Technology (ICONSET 2011)","volume":"26 1","pages":"126490Q - 126490Q-3"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77998159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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