snp biochip with electrical detection and gold nanoparticles

1 微機電熱流控制實驗室MEMSMEMS Thermal Control Lab. Thermal Control Lab.

SNP Biochip with Electrical Detection anSNP Biochip with Electrical Detection and Gold Nanoparticlesd Gold Nanoparticles

陳炳煇教授

Prof. Ping-hei Chen

Department of Mechanical Engineering

National Taiwan University


Array-Based Electrical Detection of DNA wiArray-Based Electrical Detection of DNA with Nanoparticle Probesth Nanoparticle Probes

Single Nucleotide Polymorphism (SNP)


NanoDevice

NanoDeviceNanoMaterial

Nanoparticles SNP Chip Self Assembly measurement

Integration Material Properties

Device


PROCESS BY E-beam writer

100nm GAP

SNP ChipSNP Chip

100nm


100nm

e-

Principle for electrical detection of Principle for electrical detection of

DNADNA


SNP ChipSNP Chip


Self-Assembly of AuNP MonolayerSelf-Assembly of AuNP Monolayer

Si substrate

Silicon Oxide

O OOSi Si Si Si

SH SH SH SH

Si

SH

Gold nanoparticle

O OOSiSi Si

S

Si

S S S

THMS

Silanization


Self-Assembly of AuNP MultilayerSelf-Assembly of AuNP Multilayer

SiSiO

SiSiO O

S S S S

HS

cDNA

S S

pDNA

OSi

OSi

OSi Si

S S S S

HS

tDNA

5'

3'

S

HS

SiO

Si

SS

SiOO

Si

SS

S

S

Gold nanoparticle

Si SiSiO O

SiO

S S S S

alkanethiol-cDNA


Single layer Multi-layer

Measurements are taken in atmosphere and at room temperature, but no solution between the electrodes


-1.00 -0.50 0.00 0.50 1.00-3.00

-2.00

-1.00

0.00

1.00

Dra

in C

urre

nt (

pA)

D ra in Voltage (V )-1.00 -0.50 0.00 0.50 1.00

-0.02

-0.01

0.00

0.01

0.02

D rain Voltage (V )

Dra

in C

urre

nt (

A)

Monolayer Mutlilayer

No AuNP

DNA with AuNP

In atmosphere, but no solution in the gap


A B

Fig: (A) Complementary tDNA hybridization before denatured (B) Complementary tDNA hybridization after denatured

FE-SEM images of the AuNPs before and after denatured


Fig: (Left) IV curve for complementary tDNA hybridization before denatured (Right) IV curve for complementary tDNA hybridization after denatured

FE-SEM images of the AuNPs before and after denatured

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0

40

80

Dra

in C

urre

nt (

uA)

D ra in Voltage (V )-1 .00 -0.50 0.00 0.50 1.00

-1.0

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0.0

0.5

1.0

D ra in Voltage (V )

Dra

in C

urre

nt (

nA)


FE-SEM images of the AuNPs multilayer by using different concentration of tDNA hybridization:

• Fig: (a) 0.1 μM, (b) 1 nM, (c) 10 pM, and (d) 1fM with the complementary cDNA and pDNA strands were assembled on the SiO2 substrates following the same procudure used for DNA detecti

on.

A B

C D


The electronic measurement results of nano-gap measured by using different tDNA concentration

• Fig: I-V curves of the nano-gap electrode measured by using different tDNA concentration which detected in the (A) 0.1 μM, (B) 1 nM, (C) 10 pM, and (D) 1fM range. Here, tDNA were cohybridized to cDNA and pDNA in 0.3 M PBS for 2 hours in all experiments


350nm

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G a te V o lta g e (V )

Results with 1 fM tDNA Concentration

Key: How to improve the area coverage with monolayer AuNP structure?


FE-SEM images of the AuNPs multilayer for single-bp Mismatch:

a b

Fig. (a) FE-SEM image for multilayer of AuNPs for single-bp mismatch tDNA hybridization before denaturing. (b) FE-SEM image of AuNPs for Single-bp mismatch tDNA hybridization after denaturing. Here, the concentration of tDNA for hybridization is 1nM. The chip was immersed into a salt solution of 0.01 M NaCl and PBS buffer for 2 hours.


FE-SEM images of the AuNPs multilayer for single-bp Mismatch:

(left) Current-voltage curve for multilayer of AuNPs with single-bp mismatch tDNA hybridization with a scanning rate of 10 mV/s.

(right) Current-voltage curve for AuNPs layer after the chip with the single-bp mismatch tDNA after denaturing.

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20

60

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0

40D

rain

Cur

rent

(uA

)

D ra in Voltage (V )-1 .00 -0.50 0.00 0.50 1.00

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1.0

D rain Voltage (V )

Dra

in C

urre

nt (

nA)


CMOS processed SNPCMOS processed SNP

temperature sensor

post-process testkey

biosensor & microstructures

• 奈米粒子暨電極式微陣列生物晶片主要可分為三個部分：生物感測部分、微結構部分、溫度感測與控制機制及後製程 testkey

24 微機電熱流控制實驗室MEMSMEMS Thermal Control Lab. Thermal Control Lab. biosensor & microstructures

25 微機電熱流控制實驗室MEMSMEMS Thermal Control Lab. Thermal Control Lab. biosensor & microstructures

Conclusions:

1. Electrical measurement for DNA detection is made possible through gold nanoparticles and nanogap electrodes.

2. A CMOS biochip using this electrical measurement for DNA detection is fabricated by TSMC. It proves that this biochip can be massively produced through a batch process. In future, this biochip can be used for a massive screening.

3. If the detection concentration of tDNA can be lowered to 1 fM, no PCR for tested sample is required for this biochip.

4. A single-bp mismatch between oligonucleotides can be detected by using the current technique.

snp biochip with electrical detection and gold nanoparticles

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