A5033062773- Optical Imaging and Spectroscopy Techniques
- Gold and Silver Nanoparticles Synthesis and Applications
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Nanoplatforms for cancer theranostics
- Luminescence Properties of Advanced Materials
- Orthopedic Infections and Treatments
- Analytical Chemistry and Sensors
- Plasmonic and Surface Plasmon Research
- Photoacoustic and Ultrasonic Imaging
- Nanoparticle-Based Drug Delivery
- Microfluidic and Bio-sensing Technologies
- Advanced biosensing and bioanalysis techniques
- Atomic and Subatomic Physics Research
- Total Knee Arthroplasty Outcomes
- Characterization and Applications of Magnetic Nanoparticles
- Crystal Structures and Properties
- Orthopaedic implants and arthroplasty
- bioluminescence and chemiluminescence research
- Biosensors and Analytical Detection
- Laser Applications in Dentistry and Medicine
- Quantum Dots Synthesis And Properties
- Micro and Nano Robotics
- Photonic and Optical Devices
- Radiation Detection and Scintillator Technologies
Clemson University
2015-2024
University of North Carolina at Chapel Hill
2023
Materials Science & Engineering
2017-2020
Bioengineering Center
2020
Society of Environmental Toxicology and Chemistry
2017
Northwestern University
2008-2011
University of Chicago
2008-2009
Argonne National Laboratory
2008
Erasmus MC - Sophia Children’s Hospital
2006-2007
Children's National
2006-2007
Copper(II) oxide nanoparticles (NPCuO) have many industrial applications, but are highly cytotoxic because they generate reactive oxygen species (ROS). It is unknown whether the damaging ROS generated primarily from copper leached nanoparticles, or nanoparticle surface plays a significant role. To address this question, we separated supernatant containing dissolved copper, and measured their ability to damage plasmid DNA with addition of hydrogen peroxide, ascorbate, both. While (measured...
We report the first inert gas sensing and characterization studies based on high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy. HR-LSPR was used to detect extremely small changes (<3 × 10−4) in bulk refractive index when switched between He(g) Ar(g) or N2(g). also demonstrate submonolayer sensitivity adsorbed water from exposure of sensor air (40% humidity) versus dry These measurements significantly expand applications space tools for plasmonic nanosensors.
A chemical warfare agent (CWA) gas detector based on surface-enhanced Raman spectroscopy (SERS) using robust nanostructured substrates and a portable spectrometer is promising alternative to existing modalities. gas-dosing apparatus was constructed simulate exposure provide platform for quantitative analysis of SERS detection. As first step toward characterizing detection from the phase, benzenethiol (BT) has been chosen as test analyte. spectra were monitored during BT adsorption onto...
Sensors based upon surface-enhanced Raman spectroscopy (SERS) are attractive because they have narrow, vibrationally specific spectral peaks that can be excited using red and near-infrared light which avoids photobleaching, penetrates tissue, reduces autofluorescence. Several groups fabricated pH nanosensors by functionalizing silver or gold nanoparticle surfaces with an acidic molecule measuring the ratio of protonated to deprotonated bands. However, a limitation these sensors is...
One of the greatest challenges in cancer therapy is to develop methods deliver chemotherapy agents tumor cells while reducing systemic toxicity noncancerous cells. A promising approach localizing drug release employ drug-loaded nanoparticles with coatings that drugs only presence specific triggers found target such as pH, enzymes, or light. However, many parameters affect nanoparticle distribution and rate, it difficult quantify situ. In this work, we show proof-of-principle for a "smart"...
The versatile optical and biological properties of a localized surface plasmon resonance (LSPR) sensor that responds to protein conformational changes are illustrated. detects in surface-bound construct the calcium-sensitive calmodulin. Increases calcium concentration induce 0.96 nm red shift spectral position LSPR extinction maximum (λmax). Addition chelating agent forces return its original conformation is detected as reversal λmax shift. As opposed previous work, this work demonstrates...
We have developed magnetically modulated optical nanoprobes (MagMOONs) to modulate the signal from fluorescent probes and thus separate it autofluorescence, electronic offsets, other background signals. These micro- nanosized particles emit fluorescence signals, indicating chemical concentrations, blink in response rotating magnetic fields. Demodulating dramatically enhances probe’s ratio. The methods promise improve immunoassays, intracellular sensing, fundamental biochemical research.
Magnetic nanocapsules were synthesized for controlled drug release, magnetically assisted delivery, and MRI imaging. These magnetic nanocapsules, consisting of a stable iron nanocore mesoporous silica shell, by encapsulation ellipsoidal hematite in silica, partial etching the core acid, reduction hydrogen. The provided high saturation magnetization was against oxidation at least 6 months air 1 month aqueous solution. hollow space between shell used to load anticancer T
Modulated optical nanoprobes (MOONs) are microscopic (spherical and aspherical) fluorescent particles designed to emit varying intensities of light in a manner that depends on particle orientation. MOONs can be prepared over broad size range, allowing them tailored applications including intracellular sensors, using submicrometer MOONs, immunoassays, 1−10 μm MOONs. When orientation is controlled remotely, magnetic fields (MagMOONs), it allows modulation fluorescence intensity selected...
In this work, sensing magnetic microparticles were used to probe both the local pH and viscosity-dependent nonlinear rotational behavior of particles. The latter resulted from a critical transition marking driven particle's crossover phase-locking phase-slipping with an externally rotating field, i.e., sudden breakdown in its linear response that can be measure variety physical quantities. simple rotation wobbling is described theoretically experimentally. ability chemical properties system...
A plasmonic switch based on the calcium-induced conformational changes of calmodulin is shown to exhibit reversible wavelength modulations in response changing calcium concentration. The extinction maximum (λmax) a localized surface plasmon resonance (LSPR) sensor functionalized with novel construct, cutinase−calmodulin−cutinase (CutCaMCut), reversibly shifts by 2−3 nm. high-resolution (HR) LSPR spectrometer resolution (3σ) 1.5 × 10−2 nm was developed detect these real-time, providing...
When X-rays irradiate radioluminescence nanoparticles, they generate visible and near infrared light that can penetrate through centimeters of tissue. X-ray luminescence tomography (XLT) maps the location these radioluminescent contrast agents at high resolution by scanning a narrow beam tissue sample collecting every position. Adding magnetic functionality to particles would enable them be guided, oriented, heated using external fields, while their spectrum could imaged with XLT...
Abstract A method is developed to fabricate monodispersed biocompatible Yb/Er or Yb/Tm doped β‐NaGdF 4 upconversion phosphors using polyelectrolytes prevent irreversible particle aggregation during conversion of the precursor, Gd 2 O(CO 3 ) •H O:Yb/Er Yb/Tm, :Yb/Er Yb/Tm. The polyelectrolyte on outer surface nanophosphors also provided an amine tag for PEGylation. This employed PEGylated magnetic with Fe O as core and a shell. These have relatively high saturation magnetization (7.0 emu g −1...
Although implanted medical devices (IMDs) offer many benefits, they are susceptible to bacterial colonization and infections. Such infections difficult treat because bacteria could form biofilms on the implant surface, which reduce antibiotics penetration generate local dormant regions with low pH oxygen. In addition, these hard detect early often localized surface. Herein, an optical sensor film is developed acidosis The contains both upconverting particles (UCPs) that serve as a light...
We describe an implantable sensor developed to measure synovial fluid pH for noninvasive early detection and monitoring of hip infections using standard-of-care plain radiography. The was made a responsive polyacrylic acid-based hydrogel, which expands at high contracts low pH. A radiodense tantalum bead tungsten wire were embedded in the two ends hydrogel order monitor change length response via effective pK