Chemistry Reference
In-Depth Information
existing diagnostics in a context that will allow differentiation of conditions with
similar symptoms and improve the treatment options. Biofunctional materials and
synthesis of reversibly responsive compounds could lead to reusable tests, which
might be applicable to conditions where frequent measurements are required. The
control over structural design parameters, advances in deposition of materials
through printing will play greater roles in the realisation of the new generation
diagnostics. Studies on substate-protein/enzyme interactions, surface energy,
release characteristics, assay decay will gain momentum in the realisation of
diagnostics beyond R&D. Optimisation of capillary
fl
flow parameters in lateral-
fl
ow
devices and advanced micro
uidic devices will allow construction of assays with
improved control and sensitivity. To date, limited studies in micro
fl
uidic platforms
have employed unprocessed samples. Incorporation of sample preparation should
not be overlooked. Furthermore, the performance of assay after long-term storage,
and time-consuming sensor response in colorimetric test require further investiga-
tions. Sensing and detection technologies will also evolve. The search for sensing,
quanti
fl
cation and readout within a single equipment-free assay will play a greater
role in future diagnostics. These attributes may include user-friendly, fool-proof,
text/quantity-reporting capabilities and unexplored sensing mechanisms such as
paramagnetic particles, quantum dots, coloured latex particles, and genetically
engineered whole cells based on synthetic biology, and other novel materials
including graphene, plasmonic materials, and printable gratings [
154
-
159
].
In improving the sensitivity and providing a user-friendly interface, bioinspired
photonic structures, colloidal crystal arrays, diffraction gratings and holographic
sensors can offer newer capabilities and readout approaches [
160
165
]. Some of
these sensing and readout mechanisms might not require physically blocking or
shaping the substrate for multiplexing. Although signi
-
cant time has been devoted
to quanti
cation with smartphones/handheld readers, equipment-free approaches
should not be overlooked. The use of external readers is a barrier for existing
assays, yet this requirement will be a greater challenge in adopting newer sensing
platforms. The fast-growing mobile phone market in the developing world has
made camera phones a potential platform for quantitatively reading diagnostic
assays, and this may standardise the readout devices with improved connectivity
[
166
,
167
]. Novel approaches towards instrument-free quanti
cation of analytes
will be important contributions to the
field. Additionally, the trends show that the
micro
uidic assay formats will be exploited further by the in vitro diagnostics
industry [
168
fl
170
]. All these advances will lead to multiplexed diagnostics that are
-
capable of
c etiological agent that causes a particular
syndrome, which is a goal that has not been achieved yet. Such assays can explore
less utilised clinical samples such as tear
identifying the speci
fluid with contact lens sensors [
171
].
Existing prototypes need to be transformed into highly reproducible diagnostic
devices. Having performance data does not always yield ef
fl
cacy after deployment.
Possible small-scale trials should experiment with the feasibility and cost-effec-
tiveness after scaling up. The ultimate test in the realisation of diagnostics depends
on the acceptance from experts in the commercial diagnostics industry. Today, the
rapid diagnostics business is based on a standard lateral
fl
flow format, involving the
