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Biosensors and their
applicationsG. Rosati – BioDevices Lab
Summer School of Information Engineering SSIE 2018
Brixen
Biosensors and their
applications summary
23/07/2018 Biosensors and their applications 2
1. Biosensors fundamentals and market
2. Fabrication and characterization techniques
3. Electrochemical biosensors case studies: I. Microelectrodes for cells adhesion and
electroporation
II. DNA hybridization low-cost sensors
III. Multipurpose electrochemical lactate detection
IV. Inkjet printed sensors for antibiotics and phages
detections
1. Biosensors fundamentals
and market: sensors
23/07/2018 Biosensors and their applications 3
Following the Oxford English Dictionary
definition, a sensor is a device that detects or
measures a physical property and records,
indicates or otherwise responds to it.
1. Biosensors fundamentals
and market: sensors
23/07/2018 Biosensors and their applications 4
1. Biosensors fundamentals
and market: sensors
23/07/2018 Biosensors and their applications 5
1. Biosensors fundamentals
and market: BIOsensors
23/07/2018 Biosensors and their applications 6
The analyte is the specific target substance or chemical
constituent of the sensor detection.
A transducer converts an observed event, physical or
chemical, into a measurable signal, whose magnitude is
proportional (related) to the concentration of the analyte.
A biosensor is a device for the detection of
a specific analyte that combines a
biological element with a transducer.
23/07/2018 Biosensors and their applications 7
1. Biosensors fundamentals
and market: BIOsensors
23/07/2018 Biosensors and their applications 8
Grand View Research, 2015
The biosensors impact on the society
1. Biosensors fundamentals
and market: market
923/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: market
Biosensors in the medical field
1023/07/2018
1. Biosensors fundamentals
and market: marketBiosensors revenue by application
A. Antoniacci - The global biosensor market incomes from specific detection application (2009).
1123/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: definitions
Selectivity: is the ability to discriminate between different
substances (analytes).
1223/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: definitions
Sensitivity: Is the minimal detectable analyte
concentration change.
IUPAC (International Union of Pure and Applied Chemistry)
defines sensitivity as the slope of the linear part of the calibration
plot.
1323/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: definitions
Accuracy: Is the degree of
closensess of
measurements of a quantity
to the quantity’s true value.
Precision: Is the degree to
which repeated
measurements under
unchanged conditions show
the same results.
1423/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: definitions
Response time: Time needed by the sensor to produce
a stable response.
Recovery time: Time that elapses after a measurement
before the sensor is ready to analyze the next sample.
Working lifetime: Time during which the sensor can be
used maintaining its characteristics. It’s usually
determined by the stability of the selective material.
1523/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The recognition elements are the key
component of any sensor device. They impart
the selectivity that enables the sensor to
respond selectively to a particular analyte or
group of analytes, thus avoiding interferences
from other substances
1623/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The biological recognition elements of a biosensor perform the
following two key functions:
1. It specifically recognizes the analyte.
2. It interacts with the analyte in such a manner, which produces some
physical change detectable by the transducer.
Recognition elements can be:
• catalytic activity
• high sensitivity
• high selectivity
• linear response
• requires enzyme purification
Enzymes
1723/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The biological recognition elements of a biosensor perform the
following two key functions:
1. It specifically recognizes the analyte.
2. It interacts with the analyte in such a manner, which produces some
physical change detectable by the transducer.
Recognition elements can be:
• high sensitivity
• high selectivity
• sandwich/competitive immunosensors
• long time response
Enzymes
Antibodies
1823/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The biological recognition elements of a biosensor perform the
following two key functions:
1. It specifically recognizes the analyte.
2. It interacts with the analyte in such a manner, which produces some
physical change detectable by the transducer.
Recognition elements can be:
• exploit DNA properties
• high selectivity
• stability
• long time response
• short sequences
Enzymes
Antibodies
DNA
1923/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The biological recognition elements of a biosensor perform the
following two key functions:
1. It specifically recognizes the analyte.
2. It interacts with the analyte in such a manner, which produces some
physical change detectable by the transducer.
Recognition elements can be:
• use modified cells
• variety of enzymes
• contaminations
• low selectivity
Enzymes
Antibodies
DNA
Whole cells or tissues
2023/07/2018 Biosensors and their applications
1. Biosensors fundamentals
and market: bioreceptors
The biological recognition elements of a biosensor perform the
following two key functions:
1. It specifically recognizes the analyte.
2. It interacts with the analyte in such a manner, which produces some
physical change detectable by the transducer.
Recognition elements can be:
• low cost
• high selectivity
• variety of aptamers
• high reproducibility and stability
Enzymes
Antibodies
DNA
Whole cells or tissues
Aptamers
2123/07/2018 Biosensors and their applications
2. Fabrication and
characterization techniques
There exists a wide variety of fabrication methods and even more
characterization techniques in the biosensors field.
In this lecture, we will present some of the most relevant for the
production and characterization of electrochemical biosensors:
FABRICATION
Photolithography (microfabrication)
Screen-printing
Inkjet printing
CHARACTERIZATION
Electrochemical Impedance
Spectroscopy
Cyclic Voltammetry
2223/07/2018 Biosensors and their applications
2.1 Fabrication techniques:
photolithography
Photolithography is a subtractive fabrication process where the
selective removal of material allow to obtain well resolved 3D shapes.
2323/07/2018 Biosensors and their applications
2.1 Fabrication techniques:
photolithography
Clean room fabrication allows to obtain nanostructured surfaces for specific
and sensitive materials interactions with biological molecules.
Manipulation of the matter at the atom level!
2423/07/2018 Biosensors and their applications
2.1 Fabrication techniques:
photolithography
Ref.
FE
T
Clean room fabrication allows to obtain nanostructured surfaces for specific
and sensitive materials interactions with biological molecules.
2523/07/2018 Biosensors and their applications
2.1 Fabrication techniques:
photolithography
Axon/dendrites action potential propagation Nanohole FET DNA sequencingF. Patolsky et al, Science 313 (2006) 1100. Xie et al, Nature nanoterchnology vol. 7, pg 119-125 (2011)
Screen-printing is an additive technique for the fabrication of thick-film and
low-cost devices.
2623/07/2018 Biosensors and their applications
2.2 Fabrication techniques:
screen-printing
Screen-printing is an additive technique for the fabrication of thick-film and
low-cost devices.
2723/07/2018 Biosensors and their applications
2.2 Fabrication techniques:
screen-printing
This technique is employed
also in industrial productions,
e.g. t-shirts, CDs/DVDs printing.
A different mesh
(screen) is required
per each color
(layer)
Screen-printing is an additive technique for the fabrication of thick-film and
low-cost devices.
2823/07/2018 Biosensors and their applications
2.2 Fabrication techniques:
screen-printing
Electrochemical sensors
can be produced by using
conducting and insulating
inks on rigid or flexible
substrates.
2923/07/2018 Biosensors and their applications
2.2 Fabrication techniques:
screen-printingScreen-printing is an additive technique for the fabrication of thick-film and
low-cost devices.
Smart tattoo for the stress level electrochemical
quantification (sweat sample)Glucose monitoring
strips (blood sample)
3023/07/2018 Biosensors and their applications
2.3 Fabrication techniques:
inkjet printingInkjet printing is an additive technique for the fabrication of thin-film and
low-cost devices. It can be based on:
• Thermal inkjet
• Piezoelectric inkjet
Differently from screen-printing, this technique does not require any
preparation process before printing
Thermal inkjet Piezoelectric inkjet
3123/07/2018 Biosensors and their applications
2.3 Fabrication techniques:
inkjet printingInkjet printing is an additive technique for the fabrication of thin-film and
low-cost devices. The devices can be produced both by consumer and
research-grade printers.
3223/07/2018 Biosensors and their applications
2.3 Fabrication techniques:
inkjet printingInkjet printing is an additive technique for the fabrication of thin-film and
low-cost devices.
Moya et al. SPIE Microtechnologies 2017
3323/07/2018 Biosensors and their applications
2.3 Fabrication techniques:
inkjet printingInkjet printing is an additive technique for the fabrication of thin-film and
low-cost devices.
3423/07/2018 Biosensors and their applications
2.4 Detection techniques: Electrochemical Impedance Spectroscopy
Electrochemical Impedance Spectroscopy (EIS) studies the electrode
surface by means of its IMPEDANCE.
• Possibility to detect transducer surface binding events, surface properties
changes and modifications far from the surface too.
• Impedance spectroscopy is a non-destructive technique and so can provide
time dependent information about ongoing processes.
3523/07/2018 Biosensors and their applications
2.4 Detection techniques: Electrochemical Impedance Spectroscopy
Electrochemical Impedance Spectroscopy (EIS) studies the electrode
surface by means of its IMPEDANCE.
NO redox
mediator
3623/07/2018 Biosensors and their applications
2.4 Detection techniques: Electrochemical Impedance Spectroscopy
Electrochemical Impedance Spectroscopy (EIS) studies the electrode
surface by means of its IMPEDANCE.
WITH
redox
mediator
Randle’s model
3723/07/2018 Biosensors and their applications
2.4 Detection techniques: Electrochemical Impedance Spectroscopy
Electrochemical Impedance Spectroscopy (EIS) studies the electrode
surface by means of its IMPEDANCE.
WITH
redox
mediator10
110
210
310
410
510
3.1
103.4
103.7
|Z| [
]
101
102
103
104
105
-30
-25
-20
-15
-10
-5
[°]
Frequency [Hz]
Rct + Rs Rs
1/Cdl
3823/07/2018 Biosensors and their applications
2.4 Detection techniques: Electrochemical Impedance Spectroscopy
The DC bias potential is fundamental to observe the charge transfer
resistance and depends on the particular redox mediator (E0) and on the
electrodes’ materials used.
0
2
4
6
8
10
12 0
100
200
300
400
5006
7
8
9
10
11
12
Bias potential [mV]
log(Frequency) [Hz]
Rct + Rs
Rs
1/Cdl
Lo
g(|
Z|)
[lo
g(Ω
)]
3923/07/2018 Biosensors and their applications
2.4 Detection techniques: Cyclic Voltammetry
Cyclic Voltammetry (CV) studies the behavior of redox mediators on the
electrodes and can detect/induce their oxidation (reduction).
4023/07/2018 Biosensors and their applications
2.4 Detection techniques: Cyclic Voltammetry
Cyclic Voltammetry (CV) studies the behavior of redox mediators on the
electrodes and can detect/induce their oxidation (reduction).
Input potential
CV are dynamic measurements and relies on diffusion, electrooxidation
(reduction) of mediators, thus they are difficult to model but offer a very
sensitive way to measure the electrode’s surface characteristics and to
detect electroactive molecules.
Case study IMicroelectrodes for cell adhesion
and electroporation
4223/07/2018
3.1 Case studies: microelectrodes
for cell adhesion and electroporation
The goal of this work was to monitor the electropermeabilization of
adherent mammalian cells through electrochemical impedance
spectroscopy.
• Electropermeabilization or
electroporation (EP) is the
phenomenon where the cell
membrane’s pores opens
in response to an electrical
stimulation.
• The pores opening can be used to introduce
chemicals in the cells, i.e., genetic material to
induce its mutation or to use it for the production
of specific proteins.
A. Ferrario et al. 2011, 7th Conference on PhD Research in Microelectronics & Electronics, pp. 57-60.
23/07/2018
3.1 Case studies: microelectrodes
for cell adhesion and electroporation
Cells plating on microelectrodes array (MEA) and EIS experiments showed
4 impedance groups related to the number of cells over each electrode.
A. Ferrario et al. 2011, 7th Conference on PhD Research in Microelectronics & Electronics, pp. 57-60.
23/07/2018
3.1 Case studies: microelectrodes
for cell adhesion and electroporation
Cells plating on microelectrodes array (MEA) and EIS experiments showed
4 impedance groups related to the number of cells over each electrode.
A. Ferrario et al. 2011, 7th Conference on PhD Research in Microelectronics & Electronics, pp. 57-60.
45Biosensors and their applications
3. Case studies: microelectrodes
for cell adhesion and electroporation
EIS measurements fit with the electrical model showed good results and
dependence of Rseal and β by the number of cells on the electrode.
A. Ferrario et al. 2011, 7th Conference on PhD Research in Microelectronics & Electronics, pp. 57-60.
46
3. Case studies: microelectrodes
for cell adhesion and electroporation
The evaluation of electroporation effects was performed by measuring EIS
immediately before and after the cells electrical stimulation (achieved by
the same electrodes).
As a control, a fluorescent dye was added
in the cells solutions and the electroporated
cells were compared to the not stimulated
ones for the dye inclusion.
23/07/2018
E. Pasqualotto et al. 2012, Procedia Chemistry, vol. 6, pp. 79-88.
47
3. Case studies: microelectrodes
for cell adhesion and electroporation
The evaluation of electroporation effects was performed by measuring EIS
immediately before and after the cells electrical stimulation (achieved by
the same electrodes).
23/07/2018
E. Pasqualotto et al. 2012, Procedia Chemistry, vol. 6, pp. 79-88.
48
3. Case studies: microelectrodes
for cell adhesion and electroporation
23/07/2018 Biosensors and their applications
The evaluation of electroporation effects was performed by measuring EIS
immediately before and after the cells electrical stimulation (achieved by
the same electrodes).
E. Pasqualotto et al. 2012, Procedia Chemistry, vol. 6, pp. 79-88.
49
3. Case studies: microelectrodes
for cell adhesion and electroporation
23/07/2018
From the EIS measurements fit is possible to obtain also the average
number of opened pores and an evaluation of their radius.
Potential (V) Poresnumbers
0.3 0
0.6 0
0.9 0
1.2 500
1.5 1300
1.8 2500
2.1 4500
2.4 6000
E. Pasqualotto et al. 2012, Procedia Chemistry, vol. 6, pp. 79-88.
Case study IIDNA hybridization thin-film
sensors
5123/07/2018 Biosensors and their applications
3.2 Case studies: DNA
hybridization thin-film sensors
DNA hybridization is the matching of single-sided DNA (ssDNA)
complimentary chains. DNA hybridization sensors are used to check if a
specific DNA fragment is present in a sample.
• Array of microwells for the
hybridization of different
ssDNA chains, called
microarray, are commonly
used for multiplexed
detection.
• Microarrays are based on
optical fluorescence
response, thus they require
expansive instrumentation.
5223/07/2018
3.2 Case studies: DNA
hybridization thin-film sensors
An electrochemical alternative to microarrays could help to bring the
hybridization sensors to the point of care reducing the instrumentation
costs.Low-cost devices produced engineering the
CD/DVD fabrication process with a patented
method:
Polycarbonate injection moulded
(nanostructured) substrate.
Thin-film gold patterned flat layer (sputtering,
50 nm).
Screen-printed UV-cured patterned insulating
layer.
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
5323/07/2018
3.2 Case studies: DNA
hybridization thin-film sensors
An electrochemical alternative to microarrays could help to bring the
hybridization sensors to the point of care reducing the instrumentation
costs.
MCH: 6-Mercapto-1-hexanol
(SH-(CH2)6-OH)
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
5423/07/2018
3. Case studies: DNA hybridization
low-cost sensors
EIS measurements were performed in presence of redox mediator. The
results were fit with the standard Randle’s model to obtain the charge
transfer resistance values.
With this method is possible to study both the electrode surface coverage
by ssDNA probes and to detect the complimentary ssDNA hybridization.
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
5523/07/2018
3.2 Case studies: DNA
hybridization thin-film sensors
EIS measurements in presence of redox mediator for the study of the
immobilization of ssDNA/MCH mix with 1:1 and 1:10 ratios.
0 20 40 60 80 100 120
104
105
Time [min]
Ch
arg
e t
ran
sfe
r re
sis
tan
ce
Rct [
]
2 M ssDNA/2 M MCH
2 M ssDNA/20 M MCH
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
5623/07/2018
3.2 Case studies: DNA
hybridization thin-film sensors
Probe surface density for hybridization detection optimization.
0.002 0.02 0.2 2 2010
3
104
105
106
MCH concentration [M]
Ch
arg
e t
ran
sfe
r re
sis
tan
ce
Rct [
]
MCH
MCH/2 M ssDNA
MCH/2 M ssDNA/1 M target
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
5723/07/2018
3. Case studies: DNA hybridization
low-cost sensors
EIS detection of ssDNA hybridization requires the use of spacers
between the ssDNA probe chains in order to enhance the ssDNA target
detection sensitivity.
The system can be easily
implemented in a multiplexed
format by adjusting the device
layout.
A. Ferrario et al. 2012; Procedia Chemistry, vol. 6, pp. 36-45.
Case study IIILactic acid sensing in cell
cultures, sport, and medicine
O2
Lactate
H2O2
Pyruvate
LOx
2e- + 2H+
NAD+
Lactate
NADH
Pyruvate
LDH
2e- + H+
5923/07/2018
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
Lactic acid is a metabolite involved in many biological processes such
as hypoxia in clinical and sport applications, food spoilage by bacteria
contamination, and food fermentation industry (cheese, wine).
As glucose, lactic acid (or lactate) detection is usually performed by
enzymatic reactions, such as lactate oxidase (LOx) or lactate
dehydrogenase (LDH).
Results under publication
6023/07/2018 Biosensors and their applications
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
As glucose, lactic acid (or lactate) detection is usually performed by
enzymatic reactions, such as lactate oxidase (LOx) or lactate
dehydrogenase (LDH).
The enzymes react specifically with lactate and the products of their
reactions are the analytes to be detected by the sensors or by other
techniques.
UV-Vis spectroscopy Cyclic Voltammetry
Results under publication
6123/07/2018 Biosensors and their applications
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
The NADH detection can be performed on screen-printed electrochemical
biosensors by Cyclic Voltammetry and also measuring the current at a
fixed potential.
Results under publication
6223/07/2018 Biosensors and their applications
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
The NADH detection can be performed also optically, by its specific
absorbance peak at 340 nm. The LDH enzyme production of NADH in
presence of Lactate can be monitored at 340 nm in real-time.
Results under publication
6323/07/2018 Biosensors and their applications
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
The correlation between the optical and electrochemical determinations
of the NADH produced by the enzyme in presence of Lactate is high.
However, the efficiency
of the Lactate-NADH
conversion is lower than
2% and depends on the
enzyme isoform.
However, there are
strategies to drastically
increase the efficiency.
𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 = 100[𝑁𝐴𝐷𝐻]
[𝐿𝐴]
Results under publication
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
Rapid removing of pyruvate shifts the reaction equilibrium towards the
NADH formation, increasing the LA-NADH conversion efficency.
61Biosensors and their applications23/07/2018Results under publication
65
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
Biosensors and their applications23/07/2018
Use of the LDH-GPT protocol and of CV measurements on screen-
printed electrodes for the detection of LA produced by cell cultures
incubated over time in DMEM and DMEM+FBS at 37°C.
Results under publication
66
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
Biosensors and their applications23/07/2018
Use of the LDH-GPT protocol and of CV measurements
on screen-printed electrodes for the detection of LA
before and after exercise in mice plasma.
Results under publication
Biosensors and their applications
67
3.3 Case studies: Lactic acid
sensing in cell cultures, sport, and
medicine
Biosensors and their applications23/07/2018
Use of the LDH-GPT protocol and of CV measurements on screen-
printed electrodes for the detection of LA in sweat during physical
exercise.
Results under publication
Case study IVInkjet printed biosensors for
antibiotic and viruses detection
6923/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
• Inkjet printing is familiar as a method of printing text and images onto
porous surfaces (Calvert, 2001).
• Since the 80s this technology has been increasingly used in research
laboratories around the world for the fabrication of whole (bio)chemical
sensing devices (Li, 2012).
• This technology provides distinct advantages over other fabrication
processes (Komuro et al.
2013), such as:
High speed/resolution
Low-cost
User friendly
7023/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
• Office inkjet printer loaded with commercially-available AgNP-based ink.
• Design and print of 100-500 µm wide AgNP lines
on office paper, glossy paper, and coated PET.
• AgNP lines morphological and electrical characterizations.
100 µm
200 µm
300 µm
400 µm
500 µm
Desig
nP
rint
Glossy photo paper
100 µm nominal width
~150
µm
~0,8 µm
Results under publication
Electrochemical Impedance Spectroscopy (EIS) measurements of the lines.
Admittance @10 Hz and linear fit with respect to measured width (Wmeas) for
sheet resistance (Rsheet) calculation.
71
*Required heating to 150-300°C
Substrate Rsheet (mΩ)
Glossy photo
paper112,7
Paper 8312,6
Coated PET 137,7
Kodak paper 56,9* (Shen 2014)
Glass 301,0*(Lee 2005)
Paper 696,0 (Määttänen 2012)
PET 467,0* (Ihalainen 2012)
23/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Results under publication
23/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Design, printing and test of interdigitated electrodes (IDE) for affinity
biosensing applications.
Development of a 6 channel workbench with
plug in connection.
Verification of electrodes dimensions for high
devices reproducibility.
Definition of paper devices resistance to
solution absorption and to multiple rinse (10).
Results under publication
23/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
10-1
100
101
102
103
104
105
106 1 10 20 30 40 50 60 70 80 90
101
102
103
104
Time [min]
Impedence measurement of PBS Kinetics
Frequency
Ma
gn
itu
de
|Z
| [
]
IDE stability in 10 mM Phosphate Buffered Saline (PBS) buffer pH 7.4
Initial change of the
low frequency
impedance (Rct).
Drift of the solution
resistance due to
evaporation (Rs).
Slight drop of the
impedance after 1
hour (Rct).
Results under publication
Design, printing and equivalent
electrical circuit modelling in PBS
of interdigitated electrodes (IDE)
for biosensing applications. CdlRs
Rel (fixed) CIDE
wl
23/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Results under publication
Self Assembling Monolayers (SAM)
are molecules that autonomously
form monolayers on plain surfaces.
SAM are often used in order to
simulate binding events on the
electrode’s surface and to verify
their detectability by EIS, which
defines the electrodes quality for
the biosensor realization.
75
6-mercapto-1-hexanol (MCH) is a
SAM molecule which has a thiol head
group that covalently binds to metals.
Impedance kinetics at 10 Hz of 1 mM MCH binding to the IDE
10 mM MCH
PBS
1 mM MCH
in PBS
23/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Results under publication
7623/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
A topic that is attracting the public attention is the presence of
antibiotics in meat and milk, which reflects the abuse of
antibiotics in animal breeding.
These antibiotics presence is dangerous both in the short and
long-term perspective:
• In the short term it can cause adverse reactions like
allergies.
• In the long term the antibiotics abuse constitutes the base of
the antibiotic resistance development.
Ampicillin is one of the most diffused antibiotics
and aptamers for its specific detection are
commercially available.
Results under publication
7723/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Test
electrodes
Aptamer
functionalized
Control
electrodes
NOT
functionalized
Ampicillin
spiked milk
tests
Results under publication
7823/07/2018 Biosensors and their applications
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Bacteriophages or phages are viruses that attack bacteria only,
replicating within them, and causing their death (Duckworth, 1976)
Cheese, yoghurt, and wine are
produced by adding bacterial
cultures (starter cultures) to the
unprocessed raw material, that
cause controlled fermentation
and acidification.
Lactic bacteriophages are one of the biggest problems for dairy and wineindustry because they stop fermentation processes, and lead to low quality products (in terms of nutritional values, taste and consistency) (Sillankorva et al. 2012, Jonczyk et al. 2011)
Phages
Bacteria
100 nm
Results under publication
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
13/06/2018 28th Anniversary World Congress on Biosensors 79
IDEA layout and assembled system
Time (hours)
|Z| (Ω)
M17
Culture medium
(STABILIZATION)
M17+
Bacteria
(GROWTH)
M17+
Bacteria+
Phages
(ATTACK)
4 7 25
BACTERIA
INJECTION
PHAGES
INJECTION
//EIS START EIS STOP
Cycling of the EIS
measurements on the
channels by switch
matrix.
Results under publication
13/06/2018 28th Anniversary World Congress on Biosensors 80
3.4 Case studies: Inkjet printed
biosensors for antibiotic and viruses
detection
Full EIS spectra cycling over the 8 channels:o Channels 1-4: M17 + Bacteria + Phage buffer
o Channels 5-8: M17 + Bacteria + Phages
M17 + Bacteria + buffer
M17 + Bacteria + phages Selection of the 0.1 Hz
frequency for the
kinetics plots
Normalization of
impedance magnitude
and phase values:
With k1 and k2 chosen to
start from zero.
∆𝐵𝑎𝑐𝑡 = 𝑍𝑔𝑟𝑜𝑤𝑡ℎ − 𝑍𝑠𝑡𝑎𝑏 − 𝑘1
∆𝑃ℎ𝑎𝑔𝑒 = 𝑍𝑎𝑡𝑡𝑎𝑐𝑘 − 𝑍𝑠𝑡𝑎𝑏 − 𝑘2
Results under publication
Take home
messages
Take home messages:
Biosensors
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Biosensors are devices which detects specific
analytes by combining a transducer and a
biological part.
Biosensors impact on the market will increase
in the next years in the medical, food, and
environmental sectors.
Biosensors’ performance can be compared by
assessing their specificity, sensitivity, accuracy,
precision, response/recovery times.
Take home messages:
Fabrication
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Costs Prototypingtime
Processcomplexity
Resolution
Clean-room High High High +++
Screen printing Medium Medium Medium ++
Inkjet printing Low Low Low +
Clean-room Screen-printing Inkjet-printing
Inkjet printing Vs standard techniques for sensors production:
Take home messages:
Characterization
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Electrochemical methods are just few of the
available characterization techniques in the
biosensors field.
EIS and CV are two of the most used
techniques between electrochemical methods.
EIS and CV allows the quantification of
electrodes surface coverage by biological
molecules.
Take home messages:
Case studies
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Monitoring of the electroporation of adherent mammalian cells through
electrochemical impedance spectroscopy is possible and more
efficient than fluorescence testing.
Biosensors and their applications
Take home messages:
Case studies
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DNA hybridization can be detected by EIS on thin-film low-cost sensors
and the detection efficiency depends on the ssDNA probe density.
Biosensors and their applications
Take home messages:
Case studies
87
Lactic acid can be detected by screen-printed electrochemical biosensors
in cultures medium, plasma, and sweat with an efficiency over 70%
using a two-enzyme protocol.
Biosensors and their applications
Take home messages:
Case studies
Inkjet printed biosensors can be used to detect Ampicillin by aptamer
functionalization and phages by bacterial culture impedance monitoring
over time.
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Thank you for your
attention!
23/07/2018 Biosensors and their applications 88
BioDevices Lab.http://biodevices.dei.unipd.it/
Prof. Alessandro Paccagnella
Giulio Rosati, PhD
ARC
Centro Ricerche Applicatehttp://www.arc-projects.it/
Alessandro De Toni, PhD
Elisabetta Pasqualotto, PhD
Matteo Scaramuzza, PhD