A Portable Biosensor System for Pathogen Diagnostic Applications
Lang Yang
1, Jessie Filer
2, Tom Chen
1,31
Electrical & Computer Engineering Department,
2Cell and Molecular Biology ,
3School of Biomedical Engineering, Colorado State University
The authors would like to thank Colorado State University for a Catalyst for Innovative Partnerships grant to support the work presented in this paper. The authors would also like to thank August Demann from Physics department at Colorado State University for assistance in metal evaporations during the electrode manufacturing process.
ACKNOWLEDGMENT
Biosensor is a device that can introduce analyte into nowadays
digital world through bio-elements , and present people a straightforward representation of their existence.
What’s a biosensor
Electrochemical detection
System Level Implementation
Project Overview
Zika protein were used as target, the preliminary data from
commercial instrument showed
the response from target protein is stronger than non-specific ones
when binding with probe antibody.
• A biosensor platform was designed and tested. The resulting errors were reasonably good impedance/capacitance measurements.
• Future work lies in the test of actual virus/bacteria/protein/DNA. • The platform will be further tested to do 4 electrode system and
gets ready for other electrochemistry detection approaches, such as CV, DPV and potentiometry/amperometry.
Conclusions and future work
Figure 2. (a) Dummy circuit measurements in Bode plot. (b) Redox
measurements in Nyquist plot.
200u m 10-1 100 101 102 103 104 105 0 1000 2000 3000 Frequency (Hz) Im pedanc e ( O hm s ) Bode plot This approach Benchtop Ideal 10-1 100 101 102 103 104 105 -80 -60 -40 -20 0 Frequency (Hz) P has eS hi ft ( degr ees ) This approach Benchtop Ideal
Electronics were tested by both dummy RC model and chemicals can generate reduction-oxidization current (Redox couple, Fe(CN)3-/4-) .
The data are presented in Bode and Nyquist plot in comparison with commercial benchtop. a b
Bio-element
Enzymes Nucleic Acid Antibodies Oxidase Poly-saccharide Antibodies Infected analyte XXX Positive Healthy analyte XXXNegative Electrochemical method is used as a transducer to present the
signal of the analyte. Depends on the interact type, binding or recognizing, the bio-sensing interface can behave different
electrical property, which can be used as the very signature for identification.
Electrode
Molecule as circuit is a concept that views all molecule have their
equivalent circuit model to describe their electrical response. The circuit model is typically formed by resistors and capacitors in
series or parallel.
VS
VS
Conceptual View
Electrical View
Design electrode
Electrode type, geometry, manufacturing…
Choose Bio-element and protocal
Specific antibody, complementary DNA…
Specify target
Zika, chikungunya, HIV…
Design electronics
ATSAM3X8EA
12 bit
ADC 12 bitDAC
OPAMP 12 bit DAC Ret Cdl Rs Sensor Vref Vin Rref Cf1 Cf6 ... SP I po rt Vout 12 bit ADC U AR T Po
rt Non-volatile memory Processor/
D ig it al I/O HM-10 Mux User
Design User interface
Decide user’s terminal device (PDA, cellphone, standalone display )
Data process and transmission
Process analog signal to data Wired or not wired (Wifi, BT)
Whole system is illustrated as below. It can be power by a
rechargeable battery. The prototype case was printed by 3D printer. An app was developed on android system to allow user to receive real time data measured from the biosensor through Bluetooth 4.0.
Target in sample
No Target
Deliverable Package
3D Printing or molded manufacturing
