et al. [ 97 ]. Amplification chip contains microfabricated platinum heater structures
on the bottom of silicon base. Feed channels and inlet–outlet ports are bonded to
SOG film (bond strength: maximum 83 psi) with PCR cycle control by thermal
cycle functionalized using sensing thermocouple. 527 fragments of IBR viral
genome with 0.07 pg/μL concentration have been amplified in 51 PCR cycles.
Figure2.30shows the schematic of the fabricated device.
Negligible nonspecific binding of template DNA to the hydrophobic interiors
has been shown by fluorescence measurement design. Fabrication of a microchip
platform for sensitive detection of microorganisms using integrated sorting; con-
centration and real time PCR based detection system is done by Nayak
et al. [ 98 ]. Microchip is designed in such a way that to it pre-concentrates the
specific microorganisms from highly dilute sample and real time molecular iden-
tification is performed using q-PCR process in a pico-litre micro-channel by use of
optimized interdigitated electrodes and micro-scale thermal cycling mechanism.
Gold nanoparticles (coated with secondary antibody (Goat anti-mouse IgG)) are
attached to targeted microorganisms (E-coli DH5α) to mediate immune-
conjugation. Sorting and concentration is done through dielectrophoresis (DEP)
technique and finally detection is done by quantitative-PCR (q-PCR) using fluores-
cence measurement. A primary anti E. coli antibody captured E. coli DH5αcells
with binding through nanoparticle bridges. Figure2.31shows schematic of detec-
tion of molecules.
Fluorescence detection has shown that the DEP frequency is different for the
micro-organisms with conjugation and without conjugation. Additionally the fluo-
rescence pattern observed was seen different for in case of conjugated and
non-conjugated bacterial cells (Fig.2.32).
An on-chip system for the electrokinetic capture of bacterial cells and their
identification using PCR is designed by Bhattacharya et al. [ 99 ] using a PCB
Fig. 2.29 PCR process (a) Process description; (b) Temperature requirement during PCR process
2 Microfluidics Overview 69