Chemistry Reference
In-Depth Information
(a)
(b)
(i)
(ii)
(i)
(ii)
(iii)
(iv)
4mm
(c)
(d)
(ii)
(i)
(i)
1.4 cm
(ii)
(iii)
SOP substrate
0.5 cm
Figure 18.5
Some examples of LOCs with electrochemical detection. (a) Paper-based microfluidic system;
electrodes (i), paper channel (ii), paper (iii), tape (iv), hydrophobic barrier (v) (detection using fluoresce dyes)
[71]. Adapted by permission of The Royal Society of Chemistry © 2010. (b) Microfluidic channel (i),
electrochemical electrodes (ii), air chamber (iii), microchannel (iv). Adapted from [72] © 2003 American
Chemical Society. (c) Amperometric glucose sensor (i), TEM lithography electrode. Adapted from [73] © 2007
IEEE. (d) Impedance interdigitated electrode; ITO coating (i), glass substrate (ii), 25 pairs of finger electrodes
with 15
m
m of digit and interdigit width (iii). Adapted from [74] © 2004 American Chemical Society.
(Figure 18.6b); contactless detection using an electrode to measure the change of impedance when the
influenza virus concentration change is also reported [77] (See Figure 18.6c).
18.5
Conclusions and future perspectives
Micro- and nanomaterials based detection systems applied in lab-on-a-chip technology are showing to be
interesting alternative devices for Green Analytical Chemistry. Their benefits in relation with the system
integration are being combined with the greatly reducing of the waste amount of solvents and samples
provided by the LOC systems. The developed systems provide both environmental and cost/efficiency
benefits making the analytical procedures more sustainable.
The micro- and nanomaterial based detection systems integrated into LOC show several advantages in
comparison to the classical analytical methods. Nanomaterials are showing to be of particular interest in
developing high sensitive (bio)detection devices with multidetection capability and compatibility with LOCs.
Various detection techniques ranging from optical, electrochemical and mass changes can be applied. They
offer different advantages in terms of the (bio)assay formats, sensitivity, selectivity, linear range of response
