About OMICS Group - PowerPoint Presentation

Slide1

About OMICS Group

OMICS Group International is an amalgamation of 

Open Access publications

 and worldwide international science conferences and events. Established in the year 2007 with the sole aim of making the information on Sciences and technology ‘Open Access’, OMICS Group publishes 400 online open access 

scholarly journals

 in all aspects of Science, Engineering, Management and Technology journals. OMICS Group has been instrumental in taking the knowledge on Science & technology to the doorsteps of ordinary men and women. Research Scholars, Students, Libraries, Educational Institutions, Research centers and the industry are main stakeholders that benefitted greatly from this knowledge dissemination. OMICS Group also organizes 300 

International conferences

 annually across the globe, where knowledge transfer takes place through debates, round table discussions, poster presentations, workshops, symposia and exhibitions

.Slide2

About OMICS Group Conferences

OMICS Group International is a pioneer and leading science event organizer, which publishes around 400 open access journals and conducts over 300 Medical, Clinical, Engineering, Life Sciences,

Pharma

 scientific conferences all over the globe annually with the support of more than 1000 scientific associations and 30,000 editorial board members and 3.5 million followers to its credit.

OMICS Group has organized 500 conferences, workshops and national symposiums across the major cities including San Francisco, Las Vegas, San Antonio, Omaha, Orlando, Raleigh, Santa Clara, Chicago, Philadelphia, Baltimore, United Kingdom, Valencia, Dubai, Beijing, Hyderabad,

Bengaluru

and Mumbai.Slide3

Keynote

:

Molecular

Sensing Based on Optical Whispering-Gallery Mode Microsensors

Zhixiong “James” Guo

3

rd

Internation

a

l

Conferenc

e

and

Exhib

i

tion

o

n

Biosenso

r

s

&

Bioelectronics

August

11

-

13,

2014,

Sa

n

Antonio,

Taxes

,

USASlide4

Rutgers  Jersey

Root

s

,

Global ReachChartered in 1766, Rutgers has a unique history

as a colonial college, a land-grant institution

,

and a state university. In 1864, Rutgers prevailed over another major college in NJ to become the state’s land-grant college.

T

he Birthplace of College Football

With

more

than

65,000

student

s

on

campuses

in

Camden,

Newark

,

and

New

Brunswic

k

,

Rutgers

is

one

of

the

nation’s

major

public institutions

of

higher

education.Slide5

Major

Campu

s

– New Brunswick/PiscatawayLand: 2,688 acresStudents: > 50,000

< 40 miles to Times Square,

NYCSlide6

Presentation Outline

Intro

d

uct

i

onWhat is whispering-

gallery mode?Lab fabrication of optical

WGM

devices Molecular sensing based on optical WGMPhysical and Mathematical DescriptionWGM senso

r in

a micro-opto-electro-fluidic system (MOEFS) Governing equations

---- Charg

e

an

d

fluid

tran

s

port

----

Dynamics of adsorption and desorption---- Maxwell’s equations

Results and Discussion



Validation with experimental measurement Influence of applied electrical potential Dynamics of adsorptionInfluence of resonance modes Sensor curves

Concl

udi

n

g

remarksSlide7

Whispering Gallery

Whis

p

er

i

ng gallery at St. Paul’s Cathedral Simul

ation of the whispering gallery at St. Paul’s

C

a

thedralThe study of acoustic whispering gallery began in St. Paul’s Cathedral,LondonLord Rayleigh was the first to describe how sound waves

were

reflected around the walls of the gallery due to

its

circu

la

r

shape

i

n

1878

The

term 'whispering gallery' has been borrowed in the physical sciences to descr

ibe other forms of whispering-gal

lery waves such as light

Images from WikipediaSlide8

Optical Whispering Galleries

Sound

wave

s

have a wavelength on order of meters. Light,

on the other hand, has a wave

l

engt

h on the order of microns or lessOptical whispering-gallery mode (WGM) occurs in small dielectric circular shapes

such

as spheres, rings, or cylinders, with diameters on the micrometer

scale

Optical

WGM

resona

tors

ar

e

c

haracter

ized as having extremely high Quality factors (Q- factors) and very small mode

volumesSuch features them ideal for

micro/nano photonic devices, such a

s lasers, filters, sensors, and quantum systemsDistinct researchers include Stephen Arnold at NYU-Poly, Kerry Vahala at Caltech, Russi

a

n

scientist

V

.S.

Ilchenko, French scientist Serge Haroche (Nobel Laureate in Physics, 2012), etc.

Whis

p

ering gallery mode resonators

Im

a

ge

s

fro

m

Vaha

la 2

0

0

3

,

Natur

e

4

2

4Slide9

Fabrication of Microbeads &

Tapers

Im

a

ges from Ma, Rossmann

& Guo, 2008,J. Phys. DSlide10

Generation of

Optical

WGM

WGM occurs when light, confin

ed by total internal reflect

i

on

s, orbits near the surface of a dielectric medium of circular

geometr

y and returns in phase after each

revol

u

t

ion.

Th

e

elec

t

r

omagnetic

field can close on itself, giving

rise to resonance.

f / f 

r / r  n / nTypical resonance spectrumSensing Principle:Slide11

Example: Sensing of A

Sin

g

le

Nano-Entity0.5Single Nano

Particle1.0

0

-0.5

-1.0

W

aveguide

H

.

Quan

&

Z.

Guo

,

Nanotechnolog

y, 2007; or Haiyong Quang, Ph.D. Dissertation, Rutgers University, 2006.

Cavity of 2 µm in diameter

In contact400 nmSlide12

• Science 10

August

2

007: Vol. 317 no. 5839 pp. 783-787Received

for publication 11 May 2007Label

-Fre

e

, Single-Molecule Detection with Optical Microcavities(Dr. Zhixiong Guo proposed such a similar ideal back in

early

2005, See below)NSF Proposal Number: CTS-0541585

. Starting

Date

:

Augus

t

15

,

2005

Princi

pal Investigator: Guo, ZhixiongProposal Title: SGER: Single

Molecule-Radiation Interaction in Whisperin

g GalleryMode Evane

scent Field• Nanotechnology 18 (2007) 375702 (5pp)Received 9 May 2007. Published 22 August 2007

Sim

u

lat

i

on

of

single transparent molecule interaction with an optical microcavit

y.

Haiyong Quan

and Zhixiong GuoResults fromHaiyong

Qua

n

,

Ph.D.

Dis

s

ert

a

ti

o

n

,

Rutger

s

University

,

M

a

y

2006

Chara

c

terization

of Optical Whispering Gallery Mode Resonance and Applications• Nature Methods - 5, 591 - 596 (2008)Whispering-gallery-mode biosensing: label-free detection down to single molecules. Frank Vollmer & Stephen Arnold

Earlier

Literature

on

Sin

g

le

Molecule

DetectionSlide13

• Appl.

Phys.

Le

t

t. 80, 4057 (2002)Protein detection by optica

l shift of a resonant microcavity.

F.

Vollmer, D. Braun, A. Libchaber, M. Khoshsima, I. Teraoka, S. Arnold.Optics Letters, Vol. 28, Issue

4,

pp. 272-274 (2003)Shift of whispering-gallery modes in

microsphere

s

by

prot

e

in

ad

s

orption.

S

. Arnold, M. Khoshsima, I. Teraoka, S. Holler, and F.

VollmerSelected Topics

in Quantum Electronics,

IEEE J, vol.12 (1) , 2006Polymer microring resonators for biochemical sensing applicationsC.Y. Chao, W.

Fu

n

g

,

L

.

J. GuoAdvanced Functional Materials, vol. 15 (11),

pp. 1851

-1859,

2005Macroporous Silicon Microcavities for M

acrom

ol

ecul

e

Dete

c

tion

H.

Ouyan

g

,

M.

Christo

p

he

rse

n

,

R.

Vi

a

r

d

,

B. L. Miller and P. M. Fauchet• JQSRT, vol. 93 (1-3), pp. 231–243, 2005Simulation of whispering-gallery-mode resonance shifts for optical miniature biosensorsH. Quan and Z. Guoand many othersEarlier Literature on Layered DetectionSlide14

Proposed MOEFS with a

WGM

Sensor

Anode

/Gound

Analyt

e

inlet portBuffer

inlet port

Outlet portChannel

Gap

Optical

waveguide

Inciden

t

l

ight

T

otal

internal

r

efle

c

tion

d

ө

WGM

sensor

Charge

d

analyte

flow

di

r

ection

l

h

w

Chan

n

el

Enlarged

simulatio

n

r

egion

G

r

ound/Anod

eSlide15

Adsorption and Sensing

of

Smal

l MoleculesMolecules/AnalytesMethod

II: Filtration and trapping of analytes

in

porous layerLei and Guo 2012, Nanotech.Method I: Surface attachment of analytes Lei and Guo 201

1, Biomic

rofluidicsMolecular monolayerSlide16

Governing Equations

Cha

r

ge transporta

t

ion equationsfor the charged analyte, h

ydroxide ion and hydrogen ion.

Lang

m

uir model for adsorptionPoisson equation for electrical potentialE  F (c

i z

i )iNavier-Stokes equation

with porous

medium

model

D



2

C



i

,ci i i i i ,d i

 K V  C 

  (z w FC 

)  Ki  1, 2,3iiCt2

E

f







 



P

 2  

E



V



V





V









V









t1(  C )  K CCsads sdes st

C





K







Slide17

Governing Equations (cont.)

T

im

e

-dependent

Maxwell’s equations





 E   ;  E   H



 H  0;  H  J   E





t



t











where





 1 2

H   2 H  0  1 2 E  

2



E



0cc cr0



j

c    i





2



c





j=1,2

indicate

the ele

c

trical

condu

c

tivity

of

b

ulk

sol

ution

and

mic

r

o resonator, respectively .In-plane TE wavesE(x, y,t)  E (x, y)e eitz zH (x, y,t)  [H

(

x

,

y

)

e



H

(

x

,

y

)

e

]

e

i



t

x x y ySlide18

T

i

m

e

(

s

)

R

e

l

a

t

i

v

e

c

o

v

e

r

a

g

e

(

C

s

/



)

0

0

2

0

0

40

0

60

0

0

.

2

0

.

4

0

.

6

0

.

8

U

n

a

ff

e

c

t

E

x

p

e

ri

m

e

n

t

S

i

m

u

l

a

t

i

o

n

2

0

p

M

50

0

p

M

Valid

a

tion

wit

h

Ex

p

eriment

Sampl

e analyt

e

: Bovine

Seru

m

Alb

u

min

(BSA)

proteins that

carry neg

a

tive

cha

r

g

e

s at neutral

pH

O

n

a hy

d

rophilic

surfa

c

e, the ele

c

trostatic

attraction

b

e

tween oppo

sitel

y

cha

r

g

e

d

mat

e

rial

is often the major driving

force for a

d

sor

p

tion

of bio

molecules. In a

S

i

3

N

4

/

H

2

O

solutio

n

,

the

SiN

H

+

sp

e

cies re

m

ains the

c

h

a

r

g

e

d

3

one.

Langm

u

ir

approach

is adopted

to des

c

ribe

the protein ad

sorptio

n proc

e

ss.

The

k

e

y

ass

u

mptions are:

(a) only a mo

n

ola

y

er

for

m

s

by

ad

sor

p

tion;

(b) the ad

sor

b

ing

sur

face is comp

o

se

d

of discrete,

identic

a

l,

and

no

n

-interacting

sites

;

(c) the ad

sor

p

tion

proce

s

s for each

molecule is

ind

e

p

e

ndent;

and

(d) there is no

molecul

e

-molecule interactions

sin

ce the

c

oncentration

is v

e

ry

lo

w

.

Ads

o

rption

of

BSA

at t

w

o

di

f

ferent concentrations

onto

a

si

lica

m

icro

resonator

at p

H

6.6

in

the

absence

of

e

xternal

ele

c

tric

a

l

field

(experi

m

ental

results

by

Y

eung

et

al

.

2009,

Colloids and

s

urfa

c

es

B:

Biointerfac

e

s

)Slide19

Results: Detection of BSA

Pro

t

eins

1

0

0

0

0

1

50

0

0

T

i

m

e

(

s

)

F

r

e

qu

e

n

c

y

do

w

n

s

h

i

f

t

(

M

H

z

)

50

0

0

2

0

4

0

6

0

8

0

L

a

ng

m

u

i

r

f

i

t

t

i

n

g

1

6

.

7

V

/

c

m

50

p

M

2

3

.

3

V

/

c

m

10

p

M

T

ime

trace

of

optic

a

l

resonance

frequency

down

shifts

induced

by

B

S

A

adsorption,

showin

g

t

he

Lang

m

uir

adsorp

t

ion

pa

t

tern

2

0

4

0

6

0

C

on

c

e

n

t

r

a

t

i

o

n

(

p

M

)

F

r

e

qu

e

n

c

y

do

w

n

s

h

i

f

t

(

M

H

z

)

0

8

0

0

5

0

10

0

15

0

20

0

25

0

30

0

40

0

35

0

23

.3

V

/

c

m

16

.7

V

/

c

m

6

.

6

7

V

/

c

m

The

resonance

frequency

shift

s

versus

the

bu

l

k BSA

concen

t

rati

on

for

di

f

ferent

appl

i

ed

voltage

gradien

t

s

at

ste

ady

s

ta

t

eSlide20

Results: Aminoglycoside Adsorption

in

Porous

LayerContour of analyte concentr

ation in the porous resonator

a

nd

the equipotential lines of the electrical potential field for the case with 10 pM feed and 17.7

V/cm

A grounding electrode is placed inside the resonator t

o at

tra

c

t

the

positi

v

el

y

-cha

r

ged neomycin molecules. The porous vicinity surrounding the electrode is t

he most concentrated region, which jus

tifies the fact that,

the applied electrical potential is a predominant driven mechanism over the convection and diffusion for the charged

analyte tran

sp

o

rt.

Mole

cular

concentration near the resonator can be enhanced by a

magnitude

of

order, that is very useful for extremely low-con

c

entration molecule

d

e

tectio

n

.

Sampl

e

molec

u

les:

Ne

o

my

c

in,

an aminoglyc

o

sid

e

antibiotic,

that

carries positive charges at neutral pHSlide21

Influence of Electrical Potenti

a

l

on

AdsorptionThe aminoglycoside concentration profiles along th

e resonator radial direction with a feed concentration

of 10

pM for various applied voltage gradients.

5

1

0

1

5

2

0

2

5

E

l

e

c

t

ri

c

a

l

p

o

t

e

n

t

i

a

l

g

r

a

d

i

e

n

t

(

V

/

c

m

)

A

v

e

r

a

g

e

d

s

u

r

f

a

c

e

d

e

n

s

i

t

y

(

pg

/

c

m

2

)

0

15

0

10

0

5

0

20

0

25

0

1

0

p

M

5

0

p

M

Influ

ence of ele

c

tric

a

l

potentia

l

on t

h

e

surfa

c

e

densit

y insi

d

e

the

po

r

ous

r

eso

natorSlide22

Time Trace of Adsorpt

i

on

and

Induced WGM ShiftsThe time trace of the adsorbed aminoglycosides on the r

esonator surface for three different oper

ation ca

se

s.The resonance frequency down shifts with Langmuir fitting for two different feeding and appli

ed voltage

conditions under the first-order and second-order modes,

respectively

.Slide23

Mode Profile and Sensor

Curves

D

i

st

a

n

c

e

f

r

o

m

t

h

e

r

e

s

o

n

a

t

o

r

c

e

n

t

e

r

(



m)

N

o

r

m

a

li

z

e

d

e

n

e

r

g

y

C

o

n

c

e

n

t

r

a

t

i

o

n

(

p

M

)

0

3

3

.

5

4

4

.

5

5

5

.

5

1

3

3

.

5

4

4

.

5

5

5

.

5

0

.

2

0

.

4

5

0

0

.

6

0

.

8

3

0

4

0

6

0

7

0

8

0

9

0

1

s

t

o

r

d

e

r

m

o

d

e

2

n

d

o

r

d

e

r

m

od

e

C

on

c

e

nt

r

a

t

i

o

n

Energ

y

d

i

strib

u

tions

in

the

r

esonator

radial

di

r

ection for

t

h

e fi

r

s

t

-

and

se

c

on

d

-o

r

der

modes and

t

h

e

a

mi

n

o

c

onc

e

ntrati

o

n

p

r

ofile in and

outside

the

r

eso

nato

r

for

t

h

e

c

ase

of

17.7

V/c

m applied volt

a

ge

g

r

adient and

10

p

M

fe

e

d

co

ncentr

a

tion.

The

optical

senso

r

curves

at

ste

a

d

y

-

sta

te aminogly

c

oside

deposition.Slide24

Conclusions

A

porou

s

ring microresonator integrated in a

microelectrofluidic system can functi

o

n

as both a filter and an optical whispering-gallery mode sensor.The microelectrofluidi

c

forces augment substantially the filtration capability o

f

the

system,

whic

h

separates

the

target

molecules from its solution and enriches the

analyte deposition inside the

porous resonator.

This alters the optical properties of the resonator and shifts the optical WGM resonance frequency,

l

eadin

g

to

label-free ultrasensitive detection of small molecules

a

t pico

molar concentration levels and below

.

The

second

-orde

r

whisper

i

n

g

-galler

y

mode

si

gna

l

i

s

found

to

giv

e

greater resonance frequency shift than the commonly adopted first-order mode of other types of WGM sensors.For large molecules such as proteins, they are detectable via direct surface attachment due

to

s

urfac

e

modif

i

cation

or

electro

s

tatic

force.Slide25

Acknowledgment

This

material

is based upon work supported by NSF grants CBET-1067141 and CTS-0541585, and

by the US Department of Agriculture under grant number 2008

-

01336.

Former graduate students who made great contributions: Dr. Haiyong QuanDr. Lei HuangDr. Qiulin MaUseful discussion with Dr. Guoying Chen, Rese

arch Chemist,

at Eastern Regional Research Center, USDA Agricultural Research Service, is appreciate

d.

Thank

Y

ou!Slide26

Let Us Meet Again

We welcome you all to our future conferences of OMICS Group International

Please Visit:

www.omicsgroup.com

www.conferenceseries.com

www.pharmaceuticalconferences.com