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NER: Nanoscale Sensing and Control of Biological Processes PowerPoint PPT Presentation


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0.5. 0.0. 2.0. r 0. 1.5. -0.5. cathodic. 1.0. 0.5. Current (nA). Peak current (nA). -1.0. 0.0. 0.2. 0.4. 0.6. 0.8. 1.0. -0.5. Npx-PepCo-AuNP in KAc. -1.0. -1.5. anodic. -1.5. Npx-PepCo-AuNP in KAc + H 2 O 2. -2.0. NPx-PepCo-AuNP in KAc + NADH. -2.0. (Scan rate) 1/2.

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NER: Nanoscale Sensing and Control of Biological Processes

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Ner nanoscale sensing and control of biological processes

0.5

0.0

2.0

r0

1.5

-0.5

cathodic

1.0

0.5

Current (nA)

Peak current (nA)

-1.0

0.0

0.2

0.4

0.6

0.8

1.0

-0.5

Npx-PepCo-AuNP in KAc

-1.0

-1.5

anodic

-1.5

Npx-PepCo-AuNP in KAc + H2O2

-2.0

NPx-PepCo-AuNP in KAc + NADH

-2.0

(Scan rate)1/2

(V/s)1/2

Npx-AuNP in KAc

-2.5

0.8

0.6

0.4

0.2

0.0

-0.2

Silicon microelectronic signal processing and control

Flip and bond

Potential vs. Ag/AgCl (V)

Electrochemical sensing module

Flow network chip

Flow-channel network

Biosensor electronic chip

E-beam evaporation of Ti/Au and lift-off PR

30 µm

PECVD of Si3N4

Etch Si3N4 using CF4 plasma

Cl2 plasma treatment to convert part of Ag to AgCl

Assemble PDMS gasket to electrode substrate

Tip opening

Base opening

PET membrane

PDMS channel

14

12

T = 107

12

Inlet

10

ZZ = 0

ZZ = −3

10

8

8

ZO = +3

+2

+1

0

−1

−2

−3

6

Glass channel

Current density, FDC/r

Current density, FDC/r

6

4

4

2

2

0

0

-20

-15

-10

-5

-20

-15

-10

-5

0

5

10

15

20

0

5

10

15

20

Voltage, RT/F

Voltage, RT/F

Outlet

NER: Nanoscale Sensing and Control of Biological Processes

Collaborators:

Jimmy Xu, Brown University ~Charles R. Martin, University of Florida ~ Shana O. Kelley, University of Toronto ~ Joanne I. Yeh, University of Pittsburgh

Napat Triroj and Rod Beresford Brown University, Providence, RI

Micro cyclic voltammetry measurement

An on-chip “biology-to-digital" sensing and control system

  • Objective:

  • To provide a microelectronic and microfluidic environment as a test bed for nanoelectronic / biological interfaces; to sense and control low-level charge signals arising from redox events at nanoelectrode complexes in solution

  • Approaches and Contributions:

    • Design and calibration of a micro-cyclic voltammetry flow-chip prototype

    • Target DNA hybridization detection at the micro-cyclic voltammetry flow-chip

    • Molecular assembly of a redox enzyme system by a metallized peptide at the three-microelectrode cell

    • Development and characterization of nanoelectrode array grown on a Si substrate

    • Flow-through nanopore membrance design for efficient in situ electrochemical synthesis and detection

Analyte solution: 10 mM K3Fe(CN)6 in 1 M KNO3

Analyte I/O

  • The functionality of the microfluidic three- electrode cell is confirmed:

  • formal potential is close to the literature values

  • peak current is proportional to (scan rate)1/2

Digital I/O

Integration: Chip package  Si signal processors  nanoelectrode array  self-assembled linker system  biomolecular target

Nanoelectrode array fabrication onto working electrode

Micro cyclic voltammetry flow-chip prototype fabrication

DNA hybridization detection

Fabrication results

Electrode array process

Mask design

Collaboration with Prof. Shana O. Kelley, University of Toronto

After Cl2 plasma of Ag and lift-off

Working electrode surface area: 9 µm2

An increase in the electrocatalytic charge upon hybridization of the target DNA present at low-concentration

Analyte: 27 µM Ru(NH3)63+ and 2 mM Fe(CN)63-

2 µM thiolated ssDNA, 500 nM target DNA

Current density: 3.9 mA/cm2 compared to 0.21 mA/cm2 at a bulk gold electrode

Au dot

1 μm

Completed flow-cell chip

Nanowire array grown in FIB-patterned Al2O3; wire diameter less than 50 nm

Nanocrystal array grown from Co catalyst in FIB-patterned Al2O3

Collaboration with P. Jaroenapibal,

University of Pennsylvania

Collaboration with Prof. Jimmy Xu at Brown Univ.

Modeling and Simulation of Nanoelectrochemistry

Gold Nanotubes as Flow-Through Bioreactors for Microfluidic Networks

Molecular assembly of Npx system

In collaboration with Prof. Joanne Yeh at University of Pittsburgh Medical Center

In situ monitoring, sensing, control, and actuation of biomolecular reactions

Collaboration with Hitomi Mukaibo and Charles R. Martin, University of Florida

Andres Jaramillo (undergraduate), Florida State University

Electrocatalytic model design

A self-assembled system consists of NADH peroxidase (Npx) enzyme, a metallized peptide, and a gold nanoparticle onto a microfluidic three-electrode cell

Detection of the changes in redox signals in the presence of H2O2 and NADH

  • In a conically shaped nanotube, flow from base to tip is continually focused to the tube wall, resulting in high conversion efficiency

  • Resistance to flow can be adjusted at will by controlling the base opening, tip diameter, and cone angle

Voltage

T

Ultra-sensitive integrated enzymatic detector arrays

membrane

contact pad

Time

  • Conical nanopore PET membrane fabricated by Martin group

  • Membrane sections captured between orthogonal channels in the chip assembly process

  • Electrical connection to continuous deposited Au film on the PET membrane

Large and positive charge number of O enhances migration current at nanoelectrode

Large and negative charge number of Z suppresses the current plateau and enhances cathodic peak

  • Planar working electrode also in each channel as a control

  • Coupled channels: analyze → synthesize →analyze

Electrode cell in glass:

channel depth = 12 μm

area of WE = 2.5 x 10-5 cm2

Continuity of Au trace into channel


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