Chemistry Reference
In-Depth Information
Chapter 5
Holographic Glucose Sensors
Rapid glucose sensors have applications in the screening, diagnosis and monitoring
of diabetes at point of care. This chapter demonstrates the design, fabrication
and clinical trial of reusable holographic glucose sensors. Holographic sensors
comprised boronic acid derivative functionalised acrylamide matrices, which con-
sisted of Bragg diffraction gratings that colorimetrically report on the concentration
of glucose in aqueous solutions [
1
]. The optical properties of the sensor were
designed and characterised by computational analysis. The sensors were fabricated
by combining the advantages of multi-beam interference and in situ size reduction
of silver metal (Ag
0
) nanoparticles (NPs) by single-pulse laser writing [
2
].
Fully-quantitative narrow-band (monochromatic) readouts were attained through
spectrophotometry. The advantages of holographic sensors over other sensing
mechanisms are (i) reusability, (ii) amenable to mass manufacturing through laser
writing, (iii) readouts in visible as well as near-infrared regions of the spectrum, and
(v) reproducibility to sense glucose concentrations up to 400 mM using a low
sample volume (<500
l). Interference due to other metabolites such as lactate and
fructose was also evaluated. Trials of the sensor in the urine samples of diabetic
patients demonstrated that the sensor had improved performance as compared to
Multistix
®
10 SG read by CLINITEK Status
®
, while having comparable perfor-
mance with fully-automated Dimension
®
Clinical Chemistry System. Holographic
glucose sensors may have clinical applicability for diabetes screening or diagnosis
of bacterial urinary tract infections.
μ
5.1 Diabetes Mellitus
Diabetes is one of the most challenging health problems of the 21st century. The
global prevalence of diabetes has increased dramatically, and is now a worldwide
public health concern [
3
,
4
]. Currently, 382 million people live with diabetes. This
epidemic on the rise all over the world, and it has overwhelmed the healthcare
systems. The number of people with diabetes is estimated to reach 592 million in
less than 25 years [
5
]. In 2035, one in ten people is likely to have diabetes. Diabetes
