Lab-on-a-chip device to quantify buffer capacity of blood
File(s)
Author(s)
Gandhi, Sahir
Type
Thesis
Abstract
An accurate estimation of physiological buffer capacity and total titratable buffer
concentration of blood can give a great deal of insight into the physiological stability of a
patient and yet it remains an undervalued diagnostic marker. This thesis highlights the need
for a lab-on-chip device to quantify buffer capacity of whole blood samples by estimating
the total titratable buffer concentration.
Buffer capacity is quantified by titrating the buffer to its end point using monoprotic
acids. More sophisticated ways include electrolytic titration, i.e. producing a proton flux
using electrodes in a controlled environment. This thesis looks at a novel approach to electrolytic (coulometric) titration by inhibiting the production of OH ions during electrolysis
and titrating the sample due to the proton flux from the anode.
By definition, is the amount of acid or base added to change the pH of 1 litre of buffer
by 1 pH unit. The carbonic acid bicarbonate buffer system is the most important buffer
that maintains the body’s pH within a stable range. To quantify this buffer’s total buffering
concentration, it is important to know and indicate its titration end point which signifies
the total exhaustion of all buffering constituents. Colorimetric indicators have been used
to indicate this end point which can be quantified through cameras or spectrophotometric
techniques.
Using this novel coulometric titrator and the colorimetric end point detector, this
thesis presents a portable lab-on-chip prototype to spectrophotometrically quantify total
titratable buffer concentration. Clinically, this device could benefit patients with sickle cell
disease, nephritic disease and those admitted in accident and emergency wards.
This research work is aimed at presenting a proof-of-concept for a device that can
titrate nano-litre samples and be able to detect the end point of a titration in a controlled
way.
concentration of blood can give a great deal of insight into the physiological stability of a
patient and yet it remains an undervalued diagnostic marker. This thesis highlights the need
for a lab-on-chip device to quantify buffer capacity of whole blood samples by estimating
the total titratable buffer concentration.
Buffer capacity is quantified by titrating the buffer to its end point using monoprotic
acids. More sophisticated ways include electrolytic titration, i.e. producing a proton flux
using electrodes in a controlled environment. This thesis looks at a novel approach to electrolytic (coulometric) titration by inhibiting the production of OH ions during electrolysis
and titrating the sample due to the proton flux from the anode.
By definition, is the amount of acid or base added to change the pH of 1 litre of buffer
by 1 pH unit. The carbonic acid bicarbonate buffer system is the most important buffer
that maintains the body’s pH within a stable range. To quantify this buffer’s total buffering
concentration, it is important to know and indicate its titration end point which signifies
the total exhaustion of all buffering constituents. Colorimetric indicators have been used
to indicate this end point which can be quantified through cameras or spectrophotometric
techniques.
Using this novel coulometric titrator and the colorimetric end point detector, this
thesis presents a portable lab-on-chip prototype to spectrophotometrically quantify total
titratable buffer concentration. Clinically, this device could benefit patients with sickle cell
disease, nephritic disease and those admitted in accident and emergency wards.
This research work is aimed at presenting a proof-of-concept for a device that can
titrate nano-litre samples and be able to detect the end point of a titration in a controlled
way.
Version
Open Access
Date Issued
2015-09
Date Awarded
2016-01
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
O'Hare, Danny
Boutelle, Martyn
Publisher Department
Bioengineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)