1. Sugar sensitive Phenylboronic acid-
based hydrogels: Towards glucose
analysis in sweat
by
HENOK TESFAY
4th year project
Supervisors:
Dr. Aoife Morrin,
Dr Larisa Elena Florea
Dr. Colm Delaney
School of Chemical Sciences May 2016
1
2. Aim of the project
• To build implantable glucose sensors that can
potentially detect glucose level in our body
within a few minute.
2
4. Prevalence of Diabetes
• Diabetes caused
5.1 million deaths
in 2013. Every six
seconds a person dies
from diabetes.
Source: http://www. idf.org/about-
diabetes
4
5. Is there a cure for Diabetes?
• No cure for diabetes
• Controlling blood glucose
levels in diabetic patients is
really important but it is not
easy.
• Nowadays, glucose
monitoring is performed
using devices that measure
glucose in blood drops.
• That implicates that all
people with diabetes must
prick their finger and test
drops of blood throughout
the day.
Source: http://www.slideshare.net/funk97 /
glucose-monitoring-smart-watch
5
6. • While blood test is the most known
way of measuring glucose level,
other available body fluids are
becoming interesting targets for
non-invasive glucose measurements.
Such as : sweat, saliva and tears .
Source: google contact lens
6
7. Complex between phenylboronic acid (PBA) moiety and a
sugar molecule in aqueous solution
PBA bearing hydrogel
7
Sugar
9. 20mol%PBA gel in Glucose
• Control
• In 4mM
• In 6mM
• In 10mM
• In 20 mM
20mol%PBA gel in Fructose
• Control
• In 4mM
• In 6mM
• In 10mM
• In 20mM
9
10. 20mol%PBA gel in Glucose 20mol%PBA gel in Fructose
Width (µm) Length(µm) Width(µm) Length(µm)
Control 3495.11 1185.65 3495.11 1185.65
4mM 4083.23 1381.65 5321.40 2123.96
6mM 4412.98 19333.18 5547.18 2123.86
10mM 4495.17 1690.87 5680.85 2309.53
20mM 4752.92 2216.65 5763.33 2825.02
10
11. Time dependent swelling of Hydrogel in 10mM Fructose
solution (5mol% PBA)
0
0.1
0.2
0.3
0.4
0.5
0 10 20 30 40 50 60
SwellingRatio
Time in hrs
Fructose
𝑺𝒘𝒆𝒍𝒍𝒊𝒏𝒈 𝑹𝒂𝒕𝒊𝒐 =
𝑾 𝒇 − 𝑾𝒊
𝒘𝒊
11
12. Behaviour of 5mol% PBA Hydrogel in Glucose,
Sucrose & Fructose Solutions
12
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 1 2 3 4 5 6
SwellingRatio
Concentartion in mM
Glucose
Fructose
Sucrose
13. Behaviour of Hydrogel (20mol% PBA) in different
concentration of Glucose, Fructose & Sucrose
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3 4 5 6
swellingRatio
Concentration in mM
Glucose
Sucrose
Fructose
13
15. Glucose in 20mol% & 5mol% PBA Hydrogel
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 5 10 15 20 25
SwellingRatio
concentration of Glucose in mM
Glucose in
20mole%PBA
Glucose in 5mole%
PBA
15
16. Conclusion
• Generally, the hydrogel shown a swelling in
response to the Glucose and Fructose. But didn’t
show a response to the sucrose.
• We have been particularly interested to create
implantable glucose sensors that can potentially
detect glucose concentrations within few
minutes.
• For the best accurate measurement research being
used to develop a Glucose gel sensor based on
PBA chemistry to being measured using
impedance.
16
17. fixed voltage 20 mV
frequency range 0.1 – 10 MHz
Solartron
(Impedance)
0 5 10 15 20 25 30 35 40 45 50
0
1
2
3
4
5
C(nF)
glucose concentration (mM)
1 kHz
Acrylamide
20 mol % PBA
1 mol % bisAm
1mol % HMPP
(1:1) water/DMSO
UV light
30 minutes
Electrode Functionalisation with Hydrogel
Glucose Additions
Electrical Impedance Spectroscopy
The electrode was
immersed in buffer
solution (5mL
each electrical measurement was added
10 microliters of glucose (2.5M).
• an increase of concentration of
glucose and increase of capacitance
value.
• the change in structure of hydrogel
cause changes in dieletric properties
of the hydrogel. 18
