Research Plan
The development of new scientific concepts and technologies, especially
in emerging interdisciplinary fields, is the career goal of Dr. Paresh Ray. As
a new faculty Dr. Ray’s vision is to continue research at the interface of chemistry and biology that include
exploring new chemical strategies for the control of DNA hybridization,
creating new nanobased biosensor, designing exquisite
nanostructured biomolecular
assemblies, and enhancing our understanding of biomolecular
interaction with nanosurface. Dr. Ray thinks that new
developments in nano technology and laser
spectroscopy can substantially improve the ability to carry out the mission of
a) Gold
Nnaoparticle based NSET for RNA Folding Monitoring
Since the groundbreaking
discovery that certain RNA molecules are catalysts, a growing interest of
cellular reactions are seen to be catalyzed by 'ribozymes'
or RNA enzymes. Important functions such as translation, premessenger
RNA splicing, and tRNA maturation are carried out by ribonucleoproteins that use the RNA constituents to perform
major catalytic functions. In addition, RNA demonstrates extensive versatility
in modern biotechnology and medicine, as a gene regulatory tool, as
a therapeutic agent, and for high-throughput drug discovery. This
increasing appreciation of RNA as a crucial biopolymer demands more
than ever a clear picture of how RNA molecules fold into their
native structures, which are vital to their functional properties.
RNA's considerable importance has not yet been matched by a thorough
understanding of how linear RNA sequences fold into specific structures that
mediate complex functions. However, even at this early stage, RNA folding has
already proven to be as rich and fascinating as its protein folding
counterpart. Fluorescence resonance energy transfer (FRET) measurements
have been used to track the conformational changes of RNA. However,
the length scale for detection using FRET-based methods is limited by the
nature of the dipole-dipole mechanism, which effectively constrains the length
scales to distances on the order of <100 Ĺ (R0 
60 Ĺ). Recently it has been reported that nanomaterial based FRET is capable of measuring distances
nearly twice as far as general FRET. This proposal aims to demonstrate that
gold nanoparticle based fluorescence resonance energy
transfer can be used to track the folding of RNA and to find the intermediate
states.
b) Nanostructured Materials at the Interface to Biology
This project applies an integrated approach combining surface chemistry, biophysics and theory to engineer interfaces that give quantitative information on biological activities of DNA damage. The nano-bio- interfaces theme focuses on the intersection of biological and biomolecular science with nanoscale material science. This IRG addresses four important themes at the interface of material science and biological sciences. The first theme is about developing a technique that can detect DNA damage at very low concentration. A second theme is the nanomaterial-based detection of modification of nucleic acid bases. Third theme based on nanomaterial and polymer based detection of pathogenic RNA Fourth theme adapts a materials science approach to developing nanomaterial based photodynamic therapy.
C) Label Free
Sensing of Biological Toxin using Gold Nanoparticle
Based Spectroscopy
In this project, our aim is to develop label-free, very sensitive, and highly specific system for biological agents DNA detection using gold nanoparticles and two-photon Rayleigh scattering technique. Since fundamental understanding of the interaction between bio-molecules and nanoparticle surface in very infancy, here we also want to understand the interaction between gold nanoparticles and biological molecules. Proper understanding of the optical properties of nanoparticle-biomolecule systems would allow optimizing nanoparticle based sensing methods by increasing assay’s sensitivity and effectiveness.
d) Explosive Nano-porous
Silicon: Understanding the High Energetic Behavior
Scientists
and engineers have increasingly become involved in developing new tools for
counterterrorism measures. With the discovery of
silicon wafers, the raw starting material for computer chips, can be easily
made into tiny explosives that might be used one day to chemically analyze samples
in the field or serve as power sources for tiny electronic sensors the size of
a speck of dust, there have been several efforts on how porous silicon can be used in various possible
applications for department of defense (DOD) e.g. nanoscale
solid state explosive onto silicon chips, very fast airbag ignite. The explosive
properties of nano-porous-silicon, impregnated with
an oxidant, have been reported. Explosions
belong to the most impressive chemical reactions. The efficiency of these
chemical reactions depends on the energy yield and the rate of the chemical
reaction as well as the spatial configuration of the interacting species. A
variety of mechanisms are possible for the ignition and explosive reactions.
The main goal of this project is the understanding of high energetic explosive
behavior of nano-crystalline porous silicon.
e) Nanoparticle
Based Detection Of Biomolecules
Using Hyper-Rayleigh Spectroscopy
Conjugates
of gold nanoparticles with ologonucleotides and IgG protein are of great current
interest because it has important applications in clinical diagnosis, food and
drug industry, genetics and environmental monitoring. The long-term goal of
this proposal is to develop biosensor based on DNA, protein coated gold
nanoparticles and laser based two-photon scattering technique to detect
specific DNA hybridization assays and to quantify antibody levels in clinical
samples. The specific hypothesis is that a highly sensitive detection method
can be developed for DNA and protein using nanoparticle surface plasmon
resonance (SPR) and hyper-Rayleigh Scattering (HRS) technique. The HRS
technique will be used to measure hyperpolarizabilities of proteins and
oligonucleotides. Appropriate theoretical modeling will complement experimental
studies. This research will enable
technological advancements to develop new biosensor based on HRS technique which could be used for fast, high-throughput
screening of DNA sequences and antibodies in clinical diagnostic applications.
f)
Nanomateial Based portable NSET Probe for detection of
Explosive and Chemical Warfare Agents
Aviation
and military installation security, biological agent detection, and
counter-terrorist activities are leading national priorities. The goals of this proposal
are 1) to devolop gold nanoparticle based NSET
sensor for ultrasensitive detection of toxic organophosphorus agents
and 2) design a state-of-the-art, cost-effective and portable gold nanoparticle based sensor for detection of TNT and nerve
agents simultaneously . This
sensor will be developed in such a way that any
g) Size and Distance Dependent NSET for environmental protection
By 2025, when world population is projected to be 8 billion, improving
living standards without destroying the environment is a global challenge. Environmental
pollution has been a major concern of today’s society. Emerging contaminants can be broadly
defined as any synthetic or naturally occurring chemical or any microorganism
which have the potential to enter the environment and cause known or suspected
adverse ecological and human health effects. In some cases, release of emerging
chemical or microbial contaminants to the environment has likely occurred for a
long time. Development of sensors for detection of emerging contaminants in
water supplies is a high priority with applications in domestic preparedness
and for ensuring the safety of municipal and recreational water supplies. The
benefits of nanotechnology make it ideal for sensor development, for
environmental monitoring. This proposal aims to devolop gold nanoparticle based NSET probe for ultrasensitive
detection of toxic metal like mercury and organophosphorus
pesticides (OP) selectively and simultaneously in water and to gain fundamental understanding of the mechanism of NSET at nanoparticle
surface.
h) Understanding the cyto, geno and photo toxicity
of nanomaterials of different sizes and shapes using HaCaT keratinocytes
As we move towards making
sensor-using nanotechnology, potential nanoparticle
toxicity must be investigated before any real applications
of our probe. Studies on the cytotoxicity of nanoparticles, with respect to their size and shape, are
required in order to advance nanotechnology for environmental applications.
Ensuring that nanoparticles are safe for use in
humans and others life in environment will be a key factor in determining how
big of an impact nanotechnology has on the detection. Nanotechnology is
emerging in a wide variety of applications, yet unfortunately very little is
known about the environmental implications of engineered nanomaterials
or how nanomaterials behave in the environment when
used for remediation. Therefore, our studies will increase awareness of
potential problems. Though nanoparticle production has
been estimated to increase from 2,300 tons produced today to 58,000 tons by
2020, but it is surprising that knowledge on the toxicity effect of nanoparticle exposure is in infancy. Recently we have demonstrated that
spherical gold nanoparticles with different sizes are
not inherently toxic to human skin cells, but gold nanorods
are highly toxic due to the presence of CTAB as coating material. We have shown
that poly(styrenesulfonate)
(PSS) coated gold nanorod is not toxic. So replacing
CTAB with biocompatible and functionalization
friendly stabilizing agents is essential for using of gold nanorods
in living cells. Driven by the need, in this proposal, we propose the
systematic study of cytotoxicity of gold nanomaterials of different sizes and shapes
using HaCaT keratinocytes, a
transformed human epidermal cell line.
Current
Educational Projects:
1)
Summer
School for K12 Participants
Our aims are
to conduct outreach activities at high school and initiate a Science Line
program to help local science students in their mission of enhancing scientific
literacy to wider audiences. To raise
the number of students studying science and engineering, we must begin while
students are still formulating their career plans. We believe that the most
effective way to reach them is by transforming their teachers into effective
spokesmen for science. We believe that an investment in teacher training can
multiply itself many times over the years as motivated and highly trained
teachers inspire not only generations of students, but their peers as well. During
this funding period nine K12 students and three K12 teachers from local high
schools was trained in material science area. Anna Hodge, Elliott Glenn, Franshalla
Alexander, Eumin Lee, Ariel Dawkins, Tommie Taylor, Erica Booker, Preston Fowler and Kanieshia Mitchell are the K12 students
who spend eight weeks in our laboratories last summer. Hope Hamlin,
Yolanda Anderson and Ebonie Butler are the three K12 tecahers who spend six weeks in our Nnao-Science
Summer Program. They have worked on
several areas including preparation of nanomaterial and characterization using
optical spectroscopy technique. After finishing 6 weeks now they can prepare
gold and silver nanomaterials without any supervison. We have also published a
paper best on their work and it is now accepted in IEEE Sensor Journal
2008, 8, 693-701. K12
teachers and students also
attended two-weeks material science enhancement
classes that helped them to teach material more effectively. We have
also designed Nanoscience course for K12 students and
teachers and the course were offered during this summer school. Finally thall the three teachers developed
lesson plans which they will implement in their school class room.
2) Summer School for minority undergraduate
participations
The lack of
effective "pipelines" and "pathways" from early science
and mathematics education to successful science- and mathematics-related careers
is well recognized in the