2 Bio-microelectromechanical Systems (BioMEMS) …
39
pH 7.4 with a ratio of 5:1 (AgNPs:PBS). For the colorimetry, special acpcPNA
probes were designed and fabricated to detect synthetic oligonucleotide targets with
sequences in MERS-CoV, MTB, and HPV (DNA com ). The intensity of the color was
compared to a single-base mismatch (DNA m1 ), two-base mismatch (DNA m2 ), and
DNA nc sequences. In the presence of the DNA com the intensity decreased and was
unaffected by the mismatched and noncomplementary targets. There was a high selectivity to single-base mismatch, two-base mismatch, and noncomplementary target
DNA.
Paper-based enzyme-linked immunosorbent assays (P-ELISAs) were created by
Murdock et al. (2013) in order to measure biomolecules concentrations. In comparison to regular ELISAs, P-ELISAs are faster to make and obtain results. Neuropeptide Y was the point of interest as it is related to regulating stress, anxiety, fear, and
overall sympathetic nervous system activity (Eaton et al. 2007; Heilig 2004). The
target of this study was diagnosing Post Traumatic Syndrome and identifying the
difference between more exposed soldiers from beginners. The platform of the PELISA consisted of a wax-printed 96 (12 by 8 arrays of circular test zones)-microzone
paper plate, designed on Office PowerPoint according to the standard Costar 96-well
microtiter plate (Murdock et al. 2013). The wax covered the areas between wells,
leaving the 5.56 mm diameter wells hollowed. 3 μL of target solution was inserted
into each well, followed by blocking and addition of antibody and incubation. Each
test zone was 3 mm in diameter and needed 1.5 μL to be damp. Gold nanoparticles (AuNPs) of 16 nm were added to poly(ethylene glycol) (PEG) and cleaned by
centrifugation and buffer exchanges. Anti-rabbit IgG antibodies were linked to the
carboxylic end of the PEG. For the P-ELISA, the same process was followed except
for the AuNP-IgG which was included instead of the conventional antibody through
a silver enhancement kit (Ted Pella/BBInternational). The operation was tested by
means of a standard 96-well plate-based ELISA procedure detecting rabbit IgG with
a colorimetric substrate (Fig. 2.2). The reason behind using wax-printed paper-based
was to create an inexpensive method for carrying out biomolecular assays in small
volumes. The device allowed the limit of detection (LOD) to be reduced from nano to
picomolar scale. Additionally, it permitted a broader range of colorimetric substances
be used since the dynamic imaging ranges through conversion to grayscale. Hence,
a portable device camera can be used instead of laboratory equipment to carry out
the read out. The device increased the number of samples analyzed per dollar unit
typically spent on diagnosis while equally increased the number of patients helped.
This device holds great promises for its application in remote or resource-limited
areas.
Choi et al. (2016) developed an integrated paper-based sample-to-answer
biosensor for nucleic acid extraction and amplification at the POC. This provided
a new view to the operation of paper-based devices as the readout could be done
through visual detection or quantification using a smartphone. The device was credited as a high performance microdevice since the colorimetric detection by the naked
eye could be performed within an hour. Following this strategy, a battery-powered
heating device was introduced to amplify the nucleic acid in POC, which, coupled
with the assay, offered a rapid target detection. A Fast Technology Analysis (FTA)
39
pH 7.4 with a ratio of 5:1 (AgNPs:PBS). For the colorimetry, special acpcPNA
probes were designed and fabricated to detect synthetic oligonucleotide targets with
sequences in MERS-CoV, MTB, and HPV (DNA com ). The intensity of the color was
compared to a single-base mismatch (DNA m1 ), two-base mismatch (DNA m2 ), and
DNA nc sequences. In the presence of the DNA com the intensity decreased and was
unaffected by the mismatched and noncomplementary targets. There was a high selectivity to single-base mismatch, two-base mismatch, and noncomplementary target
DNA.
Paper-based enzyme-linked immunosorbent assays (P-ELISAs) were created by
Murdock et al. (2013) in order to measure biomolecules concentrations. In comparison to regular ELISAs, P-ELISAs are faster to make and obtain results. Neuropeptide Y was the point of interest as it is related to regulating stress, anxiety, fear, and
overall sympathetic nervous system activity (Eaton et al. 2007; Heilig 2004). The
target of this study was diagnosing Post Traumatic Syndrome and identifying the
difference between more exposed soldiers from beginners. The platform of the PELISA consisted of a wax-printed 96 (12 by 8 arrays of circular test zones)-microzone
paper plate, designed on Office PowerPoint according to the standard Costar 96-well
microtiter plate (Murdock et al. 2013). The wax covered the areas between wells,
leaving the 5.56 mm diameter wells hollowed. 3 μL of target solution was inserted
into each well, followed by blocking and addition of antibody and incubation. Each
test zone was 3 mm in diameter and needed 1.5 μL to be damp. Gold nanoparticles (AuNPs) of 16 nm were added to poly(ethylene glycol) (PEG) and cleaned by
centrifugation and buffer exchanges. Anti-rabbit IgG antibodies were linked to the
carboxylic end of the PEG. For the P-ELISA, the same process was followed except
for the AuNP-IgG which was included instead of the conventional antibody through
a silver enhancement kit (Ted Pella/BBInternational). The operation was tested by
means of a standard 96-well plate-based ELISA procedure detecting rabbit IgG with
a colorimetric substrate (Fig. 2.2). The reason behind using wax-printed paper-based
was to create an inexpensive method for carrying out biomolecular assays in small
volumes. The device allowed the limit of detection (LOD) to be reduced from nano to
picomolar scale. Additionally, it permitted a broader range of colorimetric substances
be used since the dynamic imaging ranges through conversion to grayscale. Hence,
a portable device camera can be used instead of laboratory equipment to carry out
the read out. The device increased the number of samples analyzed per dollar unit
typically spent on diagnosis while equally increased the number of patients helped.
This device holds great promises for its application in remote or resource-limited
areas.
Choi et al. (2016) developed an integrated paper-based sample-to-answer
biosensor for nucleic acid extraction and amplification at the POC. This provided
a new view to the operation of paper-based devices as the readout could be done
through visual detection or quantification using a smartphone. The device was credited as a high performance microdevice since the colorimetric detection by the naked
eye could be performed within an hour. Following this strategy, a battery-powered
heating device was introduced to amplify the nucleic acid in POC, which, coupled
with the assay, offered a rapid target detection. A Fast Technology Analysis (FTA)