Chemistry Reference
In-Depth Information
Figure 18.4
Some examples of LOCs with optical detection.
(a) 3D PDMS microfluidic for cell culture.
Detection using fluorescence dyes (i), co-culture spheroids within 1 day of culture (ii). Adapted from [67] with
permission from Elsevier © 2009; (b) whole blood flowing through the microfluidic device (i), scanning
electron microscope image of a captured NCI-H1650 lung cancer cell spiked into blood. The inset shows a
high magnification view of the cell (ii). Adapted from [68] with permission from Macmillan Publishers Ltd ©
2007; (c) sample introduction (i), reagents introduction (ii), optical visualization (iii). Adapted from [69] with
permission from Elsevier © 2009; (d) TEM image of biosensing device (i), layer of the whole microdevice (ii),
integration of the microfluidic system (iii), and fluorescence image of each channel using quantum dots as
biomarkers. Adapted from [70] with permission from Elsevier © 2009.
18.4.3
LOCs with other detections
Hybrid or multiple detection based LOC systems have also been developed. Figure 18.6 shows some
typical examples using: (a) an array of ion sensitive field effect transistors, where the gate of the transistor
is open and in contact with the solution to be detected. As a result of this work a microfluidic purification
chip for capturing of multiple biomarkers from blood samples is presented. The selective and quanti-
tive detection of two model cancer antigens in less than 20 min was demonstrated [75] (Figure 18.6a);
(b) CMOS-compatible approach to fabricate silicon nanowires (SiNW) array biosensor is represented,
capable of sensing human cardiac troponin-TCTnT in a buffer solution. Measurements taken were
conductance changes, thus providing a method of label-free detection of biomolecular species [76]
