2 Bio-microelectromechanical Systems (BioMEMS) …
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Fig. 2.23 a Schematic of endpoint detection system, b photograph of endpoint detection system
and the application software on a smartphone (Sayad et al. 2017)
2.5 Alternative BioMEMS for Colorimetric Detection
In order to improve the colorimetric biosensing strategy, different amplification
methods have been developed. Among these alternative strategies, exonuclease
(Exo)-assisted signal amplification, strand displacement amplification (SDA), and
rolling circle amplification (RCA) are promising methods. The latter has proven to
result in ultrasensitive biosensors due to its excellent properties in signal amplification. However, it creates nonspecific amplification due to the impurity of the circular
template, and generation of large fragments of single-stranded DNA (ssDNA) which
may decrease the solubility. To counterpart this disadvantage, an improved alternative
was developed (Li 2016).
Li et al. (2016) established an RCA-based colorimetric biosensor with an enhanced
nucleic acid-based amplification machine to detect attomolar microRNA (miRNA).
The machine was composed of a complex of trigger template and cytosine-rich
63
Fig. 2.23 a Schematic of endpoint detection system, b photograph of endpoint detection system
and the application software on a smartphone (Sayad et al. 2017)
2.5 Alternative BioMEMS for Colorimetric Detection
In order to improve the colorimetric biosensing strategy, different amplification
methods have been developed. Among these alternative strategies, exonuclease
(Exo)-assisted signal amplification, strand displacement amplification (SDA), and
rolling circle amplification (RCA) are promising methods. The latter has proven to
result in ultrasensitive biosensors due to its excellent properties in signal amplification. However, it creates nonspecific amplification due to the impurity of the circular
template, and generation of large fragments of single-stranded DNA (ssDNA) which
may decrease the solubility. To counterpart this disadvantage, an improved alternative
was developed (Li 2016).
Li et al. (2016) established an RCA-based colorimetric biosensor with an enhanced
nucleic acid-based amplification machine to detect attomolar microRNA (miRNA).
The machine was composed of a complex of trigger template and cytosine-rich