Biomedical Engineering Reference
In-Depth Information
most widely used biosensor is the handheld amperometric glucose sensor
(Turner, 2013). Progression of technology and an educated society have led
to the popularity of personalized health monitoring devices. h ese devices
allow users to be more in control of their health, leading towards better
quality of lives and less frequent hospital visits.
A driving force of the miniaturization of the biosensors is the tech-
nological advancement of fabrication techniques in the semiconductor
industry. h ere has been growing interest to develop miniature, portable
and low-cost biosensors fabricated using MEMS technologies. MEMS
technology has been adopted from the integrated circuit (IC) industry and
applied to the miniaturization of a large range of sensing systems includ-
ing biosensors. “Biological micro-electromechanical systems” (BioMEMS)
is a subset of MEMS devices where biosensors are fabricated using either
MEMS or IC fabrication techniques. Exciting advancement in technology
has been reported in this i eld in the recent decades. Numerous biosen-
sors have been fabricated to detect for a wide range of applications such as
water toxicants (Arlett, Myers, & Roukes, 2011; Schneider, Marison, & von
Stockar, 1996; Voiculescu
et al.
, 2013) cytotoxicity studies, drug develop-
ment, chemokinetic and chemotactic activity of cell and wound healing
assays in vitro (Aylif e, Frazier, & Rabbitt, 1999; Han, Yang, & Frazier, 2007;
Keese & Giaever, 1994; Xiao & Luong, 2005). A niche area of focus in this
i eld is as point of care (PoC) devices, which is has a wide range of applica-
tions in the areas of genetics, diagnostics, drug discovery, environment,
industrial monitoring and quality control (Satyanarayana, 2005).
h ere are many reasons why scaling down in size is benei cial for
biological analyses. Biological samples are small (nm) in size, making
micrometer-sized tools for analysis better suited than conventional labora-
tory beakers and test tubes (cm). Small lab-on-chips require only a small
amount of biological samples, enabling more experiments to be run which
leads to better result interpretation. Miniaturization also allows array of
sensing elements, making it possible to have parallel and automated analy-
ses when connected to the computer.
8.2 Label-FreeAnalysis
Label-free methods are ideal for analyzing direct interactions between
compounds and biological targets. Interactions can be in the form of
chemical response or formation of molecular receptor-ligand binding. For
bio-chemical sensors, additional chemistry other than the basic may be
