38
M. A. Espinosa-Hernandez et al.
wax printing, more complex detection chambers and a higher degree of reliability for
colorimetric detection result can be achieved (Lam et al. 2017). Some of the latest
examples of the paper-based BioMEMS used for colorimetric detection are provided
here.
Teengam et al. (2017) produced a paper-based colorimetric assay for DNA detection based on pyrrolidinyl peptide nucleic acid-induced nanoparticle aggregation in
order to have a simple and quantitative means of detecting diseases such as Middle
East Respiratory Syndrome (MERS), Tuberculosis (TB), Middle East Respiratory
Syndrome coronavirus (MERS-CoV), and Human Papillomavirus (HPV). To create
the device, a multiplex colorimetric PAD with a derived backbone from D-proline/2aminocyclopentanecarboxylic acid (acpcPNA), silver nanoparticles (AgNPs) and a
paper-based multiplex DNA sensor were used. The actual PAD was made through a
wax-printing technique, and the sensor was based on an origami concept made of two
layers, as can be seen in Fig. 2.1. The base consisted of four wax-defined channels
extending outward from the sample reservoir (6 mm i.d.) and the top layer which
had four detection and control zones (4 mm i.d.). The sample reservoir at the top
was fully punched to the bottom layer, and the top was folded over. Together with a
polydimethylsiloxane (PDMS) lid and a 6 mm diameter hole over the reservoir, they
were held together. Eight 4 mm holes and control zones were aligned to maintain
a constant pressure across the surface where the acpcPNA probe and AgNPs solution were included. The sample solution was added to the sample reservoir where
it flows through the channels to wet the colorimetric detection zones. These zones
were obtained by placing 10 μL of AgNPs in 0.1 M phosphate buffer saline (PBS)
Fig. 2.1 Design and setup of paper-based multiplex DNA sensor (Teengam et al. 2017)
M. A. Espinosa-Hernandez et al.
wax printing, more complex detection chambers and a higher degree of reliability for
colorimetric detection result can be achieved (Lam et al. 2017). Some of the latest
examples of the paper-based BioMEMS used for colorimetric detection are provided
here.
Teengam et al. (2017) produced a paper-based colorimetric assay for DNA detection based on pyrrolidinyl peptide nucleic acid-induced nanoparticle aggregation in
order to have a simple and quantitative means of detecting diseases such as Middle
East Respiratory Syndrome (MERS), Tuberculosis (TB), Middle East Respiratory
Syndrome coronavirus (MERS-CoV), and Human Papillomavirus (HPV). To create
the device, a multiplex colorimetric PAD with a derived backbone from D-proline/2aminocyclopentanecarboxylic acid (acpcPNA), silver nanoparticles (AgNPs) and a
paper-based multiplex DNA sensor were used. The actual PAD was made through a
wax-printing technique, and the sensor was based on an origami concept made of two
layers, as can be seen in Fig. 2.1. The base consisted of four wax-defined channels
extending outward from the sample reservoir (6 mm i.d.) and the top layer which
had four detection and control zones (4 mm i.d.). The sample reservoir at the top
was fully punched to the bottom layer, and the top was folded over. Together with a
polydimethylsiloxane (PDMS) lid and a 6 mm diameter hole over the reservoir, they
were held together. Eight 4 mm holes and control zones were aligned to maintain
a constant pressure across the surface where the acpcPNA probe and AgNPs solution were included. The sample solution was added to the sample reservoir where
it flows through the channels to wet the colorimetric detection zones. These zones
were obtained by placing 10 μL of AgNPs in 0.1 M phosphate buffer saline (PBS)
Fig. 2.1 Design and setup of paper-based multiplex DNA sensor (Teengam et al. 2017)