Publications by authors named "Mihail Petrov"

13 Publications

  • Page 1 of 1

Gallium Phosphide Nanowires in a Free-Standing, Flexible, and Semitransparent Membrane for Large-Scale Infrared-to-Visible Light Conversion.

ACS Nano 2020 Aug 12;14(8):10624-10632. Epub 2020 Aug 12.

Alferov University (formerly St. Petersburg Academic University), Khlopina 8/3, 194021, St. Petersburg, Russia.

Engineering of nonlinear optical response in nanostructures is one of the key topics in nanophotonics, as it allows for broad frequency conversion at the nanoscale. Nevertheless, the application of the developed designs is limited by either high cost of their manufacturing or low conversion efficiencies. This paper reports on the efficient second-harmonic generation in a free-standing GaP nanowire array encapsulated in a polymer membrane. Light coupling with optical resonances and field confinement in the nanowires together with high nonlinearity of GaP material yield a strong second-harmonic signal and efficient near-infrared (800-1200 nm) to visible upconversion. The fabricated nanowire-based membranes demonstrate high flexibility and semitransparency for the incident infrared radiation, allowing utilizing them for infrared imaging, which can be easily integrated into different optical schemes without disturbing the visualized beam.
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http://dx.doi.org/10.1021/acsnano.0c04872DOI Listing
August 2020

Non-immunogenic utrophin gene therapy for the treatment of muscular dystrophy animal models.

Nat Med 2019 10 7;25(10):1505-1511. Epub 2019 Oct 7.

Department of Surgery, Pennsylvania Muscle Institute, Penn Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

The essential product of the Duchenne muscular dystrophy (DMD) gene is dystrophin, a rod-like protein that protects striated myocytes from contraction-induced injury. Dystrophin-related protein (or utrophin) retains most of the structural and protein binding elements of dystrophin. Importantly, normal thymic expression in DMD patients should protect utrophin by central immunologic tolerance. We designed a codon-optimized, synthetic transgene encoding a miniaturized utrophin (µUtro), deliverable by adeno-associated virus (AAV) vectors. Here, we show that µUtro is a highly functional, non-immunogenic substitute for dystrophin, preventing the most deleterious histological and physiological aspects of muscular dystrophy in small and large animal models. Following systemic administration of an AAV-µUtro to neonatal dystrophin-deficient mdx mice, histological and biochemical markers of myonecrosis and regeneration are completely suppressed throughout growth to adult weight. In the dystrophin-deficient golden retriever model, µUtro non-toxically prevented myonecrosis, even in the most powerful muscles. In a stringent test of immunogenicity, focal expression of µUtro in the deletional-null German shorthaired pointer model produced no evidence of cell-mediated immunity, in contrast to the robust T cell response against similarly constructed µDystrophin (µDystro). These findings support a model in which utrophin-derived therapies might be used to treat clinical dystrophin deficiency, with a favorable immunologic profile and preserved function in the face of extreme miniaturization.
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http://dx.doi.org/10.1038/s41591-019-0594-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7274039PMC
October 2019

Reshaping the Second-Order Polar Response of Hybrid Metal-Dielectric Nanodimers.

Nano Lett 2019 02 10;19(2):877-884. Epub 2019 Jan 10.

Optical Nanomaterial Group, Institute for Quantum Electronics , ETH Zurich , 8093 Zurich , Switzerland.

We combine the field confinement of plasmonics with the flexibility of multiple Mie resonances by bottom-up assembly of hybrid metal-dielectric nanodimers. We investigate the electromagnetic coupling between nanoparticles in heterodimers consisting of gold and barium titanate (BaTiO or BTO) nanoparticles through nonlinear second-harmonic spectroscopy and polarimetry. The overlap of the localized surface plasmon resonant dipole mode of the gold nanoparticle with the dipole and higher-order Mie resonant modes in the BTO nanoparticle lead to the formation of hybridized modes in the visible spectral range. We employ the pick-and-place technique to construct the hybrid nanodimers with controlled diameters by positioning the nanoparticles of different types next to each other under a scanning electron microscope. Through linear scattering spectroscopy, we observe the formation of hybrid modes in the nanodimers. We show that the modes can be directly accessed by measuring the dependence of the second-harmonic generation (SHG) signal on the polarization and wavelength of the pump. We reveal both experimentally and theoretically that the hybridization of plasmonic and Mie-resonant modes leads to a strong reshaping of the SHG polarization dependence in the nanodimers, which depends on the pump wavelength. We compare the SHG signal of each hybrid nanodimer with the SHG signal of single BTO nanoparticles to estimate the enhancement factor due to the resonant mode coupling within the nanodimers. We report up to 2 orders of magnitude for the SHG signal enhancement compared with isolated BTO nanoparticles.
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http://dx.doi.org/10.1021/acs.nanolett.8b04089DOI Listing
February 2019

The conformation of bovine serum albumin adsorbed to the surface of single all-dielectric nanoparticles following light-induced heating.

J Biophotonics 2018 07 10;11(7):e201700322. Epub 2018 Apr 10.

Department of Nanophotonics and Metamaterials, ITMO University, St. Petersburg, Russia.

Interaction between nanoparticles and biomolecules leads to the formation of biocompatible or bioadverse complexes. Despite the rapid development of nanotechnologies for biology and medicine, relatively little is known about the structure of such complexes. Here, we report on the changes in conformation of a blood protein (bovine serum albumin) adsorbed on the surface of single all-dielectric nanoparticles (silicon and germanium) following light-induced heating to 640 K. This protein is considerably more resistant to heat when adsorbed on the nanoparticle than when in solution or in the solid state. Intriguingly, with germanium nanoparticles this heat resistance is more pronounced than with silicon. These observations will facilitate biocompatible usage of all-dielectric nanoparticles.
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http://dx.doi.org/10.1002/jbio.201700322DOI Listing
July 2018

Quantum Dot Emission Driven by Mie Resonances in Silicon Nanostructures.

Nano Lett 2017 11 10;17(11):6886-6892. Epub 2017 Oct 10.

Centre for Innovation Competence SiLi-nano, Martin-Luther-University Halle-Wittenberg , Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle (Saale), Germany.

Resonant dielectric nanostructures represent a promising platform for light manipulation at the nanoscale. In this paper, we describe an active photonic system based on Ge(Si) quantum dots coupled to silicon nanodisks. We show that Mie resonances govern the enhancement of the photoluminescent signal from embedded quantum dots due to a good spatial overlap of the emitter position with the electric field of Mie modes. We identify the coupling mechanism, which allows for engineering the resonant Mie modes through the interaction of several nanodisks. In particular, the mode hybridization in a nanodisk trimer results in an up to 10-fold enhancement of the luminescent signal due to the excitation of resonant antisymmetric magnetic and electric dipole modes.
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http://dx.doi.org/10.1021/acs.nanolett.7b03248DOI Listing
November 2017

Enhanced Second-Harmonic Generation from Sequential Capillarity-Assisted Particle Assembly of Hybrid Nanodimers.

Nano Lett 2017 09 9;17(9):5381-5388. Epub 2017 Aug 9.

Optical Nanomaterial Group, Institute for Quantum Electronics, Department of Physics, ETH Zürich , Auguste-Piccard- Hof 1, 8093 Zürich, Switzerland.

We show enhanced second-harmonic generation (SHG) from a hybrid metal-dielectric nanodimer consisting of an inorganic perovskite nanoparticle of barium titanate (BaTiO) coupled to a metallic gold (Au) nanoparticle. BaTiO-Au nanodimers of 100 nm/80 nm sizes are fabricated by sequential capillarity-assisted particle assembly. The BaTiO nanoparticle has a noncentrosymmetric crystalline structure and generates bulk SHG. We use the localized surface plasmon resonance of the gold nanoparticle to enhance the SHG from the BaTiO nanoparticle. We experimentally measure the nonlinear signal from assembled nanodimers and demonstrate an up to 15-fold enhancement compared to a single BaTiO nanoparticle. We further perform numerical simulations of the linear and SHG spectra of the BaTiO-Au nanodimer and show that the gold nanoparticle acts as a nanoantenna at the SHG wavelength.
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http://dx.doi.org/10.1021/acs.nanolett.7b01940DOI Listing
September 2017

Plasmon-assisted optical trapping and anti-trapping.

Light Sci Appl 2017 May 5;6(5):e16258. Epub 2017 May 5.

Department of Nanophotonics and Metamaterials, ITMO University, Birzhevaja Line, 14, 199034 St Petersburg, Russia.

The ability to manipulate small objects with focused laser beams has opened a venue for investigating dynamical phenomena relevant to both fundamental and applied science. Nanophotonic and plasmonic structures enable superior performance in optical trapping via highly confined near-fields. In this case, the interplay between the excitation field, re-scattered fields and the eigenmodes of a structure can lead to remarkable effects; one such effect, as reported here, is particle trapping by laser light in a vicinity of metal surface. Surface plasmon excitation at the metal substrate plays a key role in tailoring the optical forces acting on a nearby particle. Depending on whether the illuminating Gaussian beam is focused above or below the metal-dielectric interface, an order-of-magnitude enhancement or reduction of the trap stiffness is achieved compared with that of standard glass substrates. Furthermore, a novel plasmon-assisted anti-trapping effect (particle repulsion from the beam axis) is predicted and studied. A highly accurate particle sorting scheme based on the new anti-trapping effect is analyzed. The ability to distinguish and configure various electromagnetic channels through the developed analytical theory provides guidelines for designing auxiliary nanostructures and achieving ultimate control over mechanical motion at the micro- and nano-scales.
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http://dx.doi.org/10.1038/lsa.2016.258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6062188PMC
May 2017

Efficient Second-Harmonic Generation in Nanocrystalline Silicon Nanoparticles.

Nano Lett 2017 05 24;17(5):3047-3053. Epub 2017 Apr 24.

Department of Nanophotonics and Metamaterials, ITMO University , St. Petersburg 197101, Russia.

Recent trends to employ high-index dielectric particles in nanophotonics are motivated by their reduced dissipative losses and large resonant enhancement of nonlinear effects at the nanoscale. Because silicon is a centrosymmetric material, the studies of nonlinear optical properties of silicon nanoparticles have been targeting primarily the third-harmonic generation effects. Here we demonstrate, both experimentally and theoretically, that resonantly excited nanocrystalline silicon nanoparticles fabricated by an optimized laser printing technique can exhibit strong second-harmonic generation (SHG) effects. We attribute an unexpectedly high yield of the nonlinear conversion to a nanocrystalline structure of nanoparticles supporting the Mie resonances. The demonstrated efficient SHG at green light from a single silicon nanoparticle is 2 orders of magnitude higher than that from unstructured silicon films. This efficiency is significantly higher than that of many plasmonic nanostructures and small silicon nanoparticles in the visible range, and it can be useful for a design of nonlinear nanoantennas and silicon-based integrated light sources.
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http://dx.doi.org/10.1021/acs.nanolett.7b00392DOI Listing
May 2017

Resonant Nonplasmonic Nanoparticles for Efficient Temperature-Feedback Optical Heating.

Nano Lett 2017 05 24;17(5):2945-2952. Epub 2017 Apr 24.

Department of Nanophotonics and Metamaterials, ITMO University , St. Petersburg 197101, Russia.

We propose a novel photothermal approach based on resonant dielectric nanoparticles, which possess imaginary part of permittivity significantly smaller as compared to metal ones. We show both experimentally and theoretically that a spherical silicon nanoparticle with a magnetic quadrupolar Mie resonance converts light to heat up to 4 times more effectively than similar spherical gold nanoparticle at the same heating conditions. We observe photoinduced temperature raise up to 900 K with the silicon nanoparticle on a glass substrate at moderate intensities (<2 mW/μm) and typical laser wavelength (633 nm). The advantage of using crystalline silicon is the simplicity of local temperature control by means of Raman spectroscopy working in a broad range of temperatures, that is, up to the melting point of silicon (1690 K) with submicrometer spatial resolution. Our CMOS-compatible heater-thermometer nanoplatform paves the way to novel nonplasmonic photothermal applications, extending the temperature range and simplifying the thermoimaging procedure.
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http://dx.doi.org/10.1021/acs.nanolett.7b00183DOI Listing
May 2017

Suite of clinically relevant functional assays to address therapeutic efficacy and disease mechanism in the dystrophic mouse.

J Appl Physiol (1985) 2017 Mar 8;122(3):593-602. Epub 2016 Dec 8.

Perelman School of Medicine & Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania; and

Duchenne muscular dystrophy (DMD) is a progressive primary myodegenerative disease caused by a genetic deficiency of the 427-kDa cytoskeletal protein dystrophin. Despite its single-gene etiology, DMD's complex pathogenesis remains poorly understood, complicating the extrapolation from results of preclinical studies in genetic homologs to the design of informative clinical trials. Here we describe novel phenotypic assays which when applied to the mouse resemble recently used primary end points for DMD clinical trials. By coupling force transduction, high-precision motion tracking, and respiratory measurements, we have achieved a suite of integrative physiological tests that provide novel insights regarding normal and pathological responses to muscular exertion. A common feature of these physiological assays is the precise tracking and analysis of volitional movement, thereby optimizing the relevance to clinical tests. Unexpectedly, the measurable biological distinction between dystrophic and control mice at early time points in the disease process is better resolved with these tests than with the majority of previously used, labor-intensive studies of individual muscle function performed ex vivo. For example, the dramatic loss of volitional movement following a novel, standardized grip test distinguishes control mice from mice by a 17.4-fold difference of the means (3.5 ± 2.2 vs. 60.9 ± 12.1 units of activity, respectively; effect size 1.99). The findings have both mechanistic and translational implications of potential significance to the fields of basic myology and neuromuscular therapeutics. This study uses novel phenotypic assays which when applied to the mouse resemble recently used primary end points for DMD clinical trials. A measurable distinction between dystrophic and control mice was seen at early time points in vivo compared with invasive muscle studies performed ex vivo. These assays shed light on normal and pathological responses to muscular exertion and have significant mechanistic and translational implications for the fields of basic myology and neuromuscular therapeutics.
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http://dx.doi.org/10.1152/japplphysiol.00776.2016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5401958PMC
March 2017

Nanoscale patterning of metal nanoparticle distribution in glasses.

Nanoscale Res Lett 2013 Jun 1;8(1):260. Epub 2013 Jun 1.

, National Research University of Information Technologies, Mechanics and Optics, St, Petersburg, 197101, Russia.

: We show that electric field imprinting technique allows for patterning of metal nanoparticles in the glass matrix at the subwavelength scale. The formation of glass-metal nanocomposite strips with a width down to 150 nm is demonstrated. The results of near-field microscopy of imprinted patterns are in good agreement with the performed numerical modeling. Atomic force microscopy reveals that imprinting also results in the formation of nanoscale surface profile with the height going down with the decrease of the strip width. The experiments prove the applicability of this technique for the fabrication of nanoscale plasmonic components.
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http://dx.doi.org/10.1186/1556-276X-8-260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3679841PMC
June 2013

Gene transfer to muscle from the isolated regional circulation.

Methods Mol Biol 2011 ;709:277-86

Department of Surgery, Division of Gastrointestinal Surgery, University of Pennsylvania School of Medicine, BRB II/III Building, 421 Currie Boulevard, Philadelphia, PA, USA.

Vector transport across the endothelium has long been regarded as one of the central "bottlenecks" in gene therapy research, especially as it pertains to the muscular dystrophies where the target tissue approaches half of the total body mass. Clinical studies of gene therapy for hemophilia B revealed the limitations of the intramuscular route, compelling an aggressive approach to the study of scale-independent circulatory means of vector delivery. The apparent permeability of the microvasculature in small animals suggests that gravitational and/or inertial effects on the circulation require progressive restriction of fluid and solute flow across the capillary wall with increasing body size. To overcome this physiological restriction, we initially used a combined surgical and pharmacological approach to temporarily alter permeability within the isolated pelvic limb. Although this was successful, new information about the cell and molecular biology of histamine-induced changes in microvascular permeability suggested an alternative approach, which substituted pressure-induced transvenular extravasation. Here we outline the details of our surgical approaches in the rat. We also discuss the modifications that are appropriate for the dog.
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http://dx.doi.org/10.1007/978-1-61737-982-6_18DOI Listing
July 2011

Chemical speciation in mining affected waters: the case study of Asarel-Medet mine.

Environ Monit Assess 2009 Dec 7;159(1-4):353-66. Epub 2008 Dec 7.

Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl.11, 1113, Sofia, Bulgaria.

The inorganic chemical species in Maresh and Luda Yana rivers affected by the Cu- Mo Asarel-Medet mine, Bulgaria were determined during a low-flow and a high-flow period. The mining activities, the weathering and the oxidation processes strongly influenced the physicochemical processes in the whole water system. The main pollution source was a small lake receiving the acid effluents of the mining activities. High levels of SO4(2-), Cu, Mg, Al, Mn and Fe were determined at the mining polluted and affected stations. Cu(2+) and CuCO3(0) species (1:1) were present in the reference waters and Cu(2+) and CuSO4(0) species (1:1) in the polluted and affected waters; Cu(2+) species was dominating downstream. Me(2+) followed by MeSO4(0) (Me = Mn, Zn, Cd and Pb), PbCO3(0) and PbHCO3(+) species as well as Fe(OH)2(+), Al(OH)4(-), Al(OH)2(+), Al(OH)3(0) were prevailing in the system. MeSO4(+) and Me(SO4)2(-) (Me = Fe, Al), Me(SO4)2(2-) (Me = Zn, Cd and Pb), Me(SO4)3(4-) (Me = Zn, Cd) and Cd(SO4)4(6-) species polluted and affected waters. The major elements K and Na were mainly Me(+) species, whereas Ca and Mg were Me(2+) and MeSO4(0) species in different ratios. The concentration of concentration of NO2(-), NO3(-) and NO4(+) species as well as complex phosphorous species such as H2PO4(-), FeHPO4(+), HPO4(2-), CaPO4(-), CaHPO4(0) and MgHPO4(0) were also calculated. The trace element concentrations decreased downstream due to dilution, sorption processes and precipitation, but the percentage of free metal species, which are more toxic, increased. An exception was iron and aluminum of which the dominant hydroxy colloidal and sulphate species were easily incorporated into the suspended phase.
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http://dx.doi.org/10.1007/s10661-008-0634-6DOI Listing
December 2009