1. Připraveno ve spolupráci s projektem OPVK NANOTEAM
Budování výzkumných týmů a rozvoj univerzitního vzdělávání výzkumných odborníků pro mikro- a nanotechnologie (NANOTEAM)
Reg. č. CZ.1.07/2.3/.00/
Investice do rozvoje vzdělávání

2. Investice do rozvoje vzdělávání
Gold-amalgam microelectrodes array for ultrasensitive protein detection
Radim Hrdý, Camila M. Campos, Pavel Neužil
Investice do rozvoje vzdělávání

3. Investice do rozvoje vzdělávání
Outlineelectrodes Array for Ultrasensitive Protein Detection
Introduction
Electrochemical detection
Microelectrodes
Amalgam electrodes
Chip design
Chip design and fabrication
Bonding problem
Electrochemical characterization
Conclusion
Investice do rozvoje vzdělávání

4. Investice do rozvoje vzdělávání
Electrochemical protein detectionlectrodes array for ultrasensitive protein detection
Actual trends
Selective and high sensitive detection
Multi and fast detection
Low cost
High reproducibility
Sensitive method and modified electrodes
Array of microelectrodes
System integrated on the chip
Mass production
Investice do rozvoje vzdělávání

5. Electrochemical methodsArray for Ultrasensitive Protein Detection

6. Investice do rozvoje vzdělávání
„Semi - Difference Cyclic Pulse Votametry“Array for Ultrasensitive Protein Detection
Vin t
Vout t
Investice do rozvoje vzdělávání

7. Advantages of microelectrodesltrasensitive protein detection
Measurement inside the diffusion layer
Short distance between electrodes suppress the charging current
Steady-state is attained rapidly
Faster electrochemical reaction
,Andrew O. Simm, Analyst, 2005,130,

8. Mercury electrodes Wide potential window
Possibility to detect proteins or µRNA
High affinity to –SH (thiol) group

9. Chip design and fabrication
3D system of 9 x 4 electrodes array
2x 200 nm gold layer
1 um Parylen interlayer
All working electrodes are connected
Changing of interelectrode distance by electrochemical deposition
Parylen
gold
deposited metal

10. Chip design and fabricationfor ultrasensitive protein detection
Problem of bottom gold layer over etching
Proof by SEM and EDX

11. Chip design and fabricationarray for ultrasensitive protein detection
Reparation and gold deposition
0,1M KAu(CN) M H3BO4
Platinum wire as counter electrode
Poor wettability of electrolyte
Using TWEEN 80 as surfactant
Mercury deposition
Higher wettability
Short circuits of top electrodes

12. Bonding Problemsltrasensitive Protein Detection
Soldering
Differential preheating of glass chip
Poor wettability of solder
Application of high pressure
EPOTEK H31-D Conductive Glue
Elimination soldering problem
Manual deposition
New board design

13. Electrochemical characterization Ultrasensitive Protein Detection
Conditions
0.1 M KCl and K3[Fe(CN)6] + K4[Fe(CN)6] 1:1
Concentration 1 mM – 1uM
Scan rate 200 – 50 mHz = mV.s-1
Amplitude 800 mV
Fe(CN)63- + e- → Fe(CN)6 4-
Fe(CN)64- - e- → Fe(CN)6 3- V V V V

14. Electrochemical characterization Ultrasensitive Protein Detection
Gold deposition with TWEEN 80
Thickness calculated according to Faradays law – 0.5 µm V V

15. Electrochemical characterization Ultrasensitive Protein Detection
Mercury deposition
Thickest of Hg layer 0.1 µm
50 mHz V V V V

16. Investice do rozvoje vzdělávání
Summary
Ultrasensitive Protein Detection
Microelectrode array was designed
New electrochemical system was developed
Amalgame electrodes were tested
Future plans
Repeated fabrication of chips
Set the LOD (limit of detection)
Surface of electrodes bio-modification Avidin-Biotin
Testing of system selectivity
Publication: Manuscripts for JACS and LOC
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17. Investice do rozvoje vzdělávání
Acknowledgment
Ultrasensitive Protein Detection
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18. Thank you for your attention
Investice do rozvoje vzdělávání