6 Bio-microelectromechanical Systems (BioMEMS) …
147
A quick and reliable diagnosis of Crimean-Congo hemorrhagic fever (CCHF) is
vital for prevention of secondary spread from human-to-human, and for proper infection control measures and patient management (Papa et al. 2015; Conger et al. 2015;
Pshenichnaya and Nenadskaya 2015). While diagnostics mostly rely on real-time
reverse transcription polymerase chain reaction (RT-PCR) and ELISA, they require
trained personnel and expensive equipment (Algaar et al. 2015; Vanhomwegen et al.
2012). Fiber-optic biosensors are a suitable alternative to existing diagnostic options
for CCHF due to their small size, diagnostic accuracy, and low cost. They are quantitative and can easily be multiplexed and could be implemented on a multiple-target
POC assay. Algaar et al. (2015), developed a fiber-optic biosensor for the detection of CCHF IgG antibodies (Table 6.1). They expressed a plasmid containing the
nucleocapsid gene of CCHFV strain. The authors used SFS400/440B black Tefzel
Superguide G UV-vis optic fibers. Tefzel jacket and silicon buffer were both removed
with a fiber stripping tool, leaving a nude optical fiber core tip. The fibers were sonicated and treated with piranha solution to produce surface hydroxyl groups. Fibers’
surfaces were then silanized with (3-glycidoxypropyl) trimethoxysilane. Afterward,
the fibers were treated with hydrochloric acid to form vicinal diols, and with dissolved
sodium m-periodate for the oxidation to aldehyde. Fibers were then rinsed with
deionized water and incubated with HRP (for assay optimization) or CCHFV NP
(for assay validation). Unreacted aldehyde groups were blocked using glycine and
the unsaturated amines were stabilized by sodium cyanoborohydride. After exposure to a substrate, the marker enzyme oxidized it and a chemiluminescent glow was
produced as a side reaction that was collected by the optical fibers and transduced to
the detector. The CL detection was performed with the Immuno-star HRP chemiluminescent kit. The authors optimized the immobilization procedures to enhance the
overall signal (maximize the CL output). The authors found that sonication significantly increased the biosensor endpoint signal output and that methanol washing
for 20 min was the most effective for the optimization process. Moreover, the addition of 3-(10
-Phenothiazinyl) propane-1-sulfonate (SPTZ) and morpholinopyridine
(MORP) increased the biosensor’s output by tenfold as they provide a more durable
light signal that increases the biosensor’s sensitivity. The authors have enhanced
the methodology by optimizing the salinization process and achieving the highest
biosensor output with the temperature and duration of treatment with sodium mperoxidate. Their experiments showed that the fiber-optic biosensor was 10-times
more sensitive than colorimetric ELISA and was able to detect both patients with
high and low levels of IgG antibodies which makes this platform highly desirable for
early detection. The authors concluded that the assay could serve as a rapid, primary
diagnostic tool for bedside CCHF diagnostics in endemic areas where extensive
diagnostic equipment and trained personnel are not available (Algaar et al. 2015).
Yang et al. (2015) developed an Fe 3 O 4 @SiO 2 MP-based CL approach to
detect sequence-specific DNA present in infectious pathogens, by utilizing the CL
system of alkaline phosphatase (AP) and 3-(2
-spiroadamantyl)-4-methoxy-4-(3
-
phosphoryloxy) phenyl-1,2-dioxetane (AMPPD) (Tang et al. 2013; Wang et al.
2012; Li et al. 2011; Yang et al. 2015) (Table 6.1). Due to the poor detection sensitivity resultant from steric hindrance caused by DNA hybridization, the authors used
147
A quick and reliable diagnosis of Crimean-Congo hemorrhagic fever (CCHF) is
vital for prevention of secondary spread from human-to-human, and for proper infection control measures and patient management (Papa et al. 2015; Conger et al. 2015;
Pshenichnaya and Nenadskaya 2015). While diagnostics mostly rely on real-time
reverse transcription polymerase chain reaction (RT-PCR) and ELISA, they require
trained personnel and expensive equipment (Algaar et al. 2015; Vanhomwegen et al.
2012). Fiber-optic biosensors are a suitable alternative to existing diagnostic options
for CCHF due to their small size, diagnostic accuracy, and low cost. They are quantitative and can easily be multiplexed and could be implemented on a multiple-target
POC assay. Algaar et al. (2015), developed a fiber-optic biosensor for the detection of CCHF IgG antibodies (Table 6.1). They expressed a plasmid containing the
nucleocapsid gene of CCHFV strain. The authors used SFS400/440B black Tefzel
Superguide G UV-vis optic fibers. Tefzel jacket and silicon buffer were both removed
with a fiber stripping tool, leaving a nude optical fiber core tip. The fibers were sonicated and treated with piranha solution to produce surface hydroxyl groups. Fibers’
surfaces were then silanized with (3-glycidoxypropyl) trimethoxysilane. Afterward,
the fibers were treated with hydrochloric acid to form vicinal diols, and with dissolved
sodium m-periodate for the oxidation to aldehyde. Fibers were then rinsed with
deionized water and incubated with HRP (for assay optimization) or CCHFV NP
(for assay validation). Unreacted aldehyde groups were blocked using glycine and
the unsaturated amines were stabilized by sodium cyanoborohydride. After exposure to a substrate, the marker enzyme oxidized it and a chemiluminescent glow was
produced as a side reaction that was collected by the optical fibers and transduced to
the detector. The CL detection was performed with the Immuno-star HRP chemiluminescent kit. The authors optimized the immobilization procedures to enhance the
overall signal (maximize the CL output). The authors found that sonication significantly increased the biosensor endpoint signal output and that methanol washing
for 20 min was the most effective for the optimization process. Moreover, the addition of 3-(10
-Phenothiazinyl) propane-1-sulfonate (SPTZ) and morpholinopyridine
(MORP) increased the biosensor’s output by tenfold as they provide a more durable
light signal that increases the biosensor’s sensitivity. The authors have enhanced
the methodology by optimizing the salinization process and achieving the highest
biosensor output with the temperature and duration of treatment with sodium mperoxidate. Their experiments showed that the fiber-optic biosensor was 10-times
more sensitive than colorimetric ELISA and was able to detect both patients with
high and low levels of IgG antibodies which makes this platform highly desirable for
early detection. The authors concluded that the assay could serve as a rapid, primary
diagnostic tool for bedside CCHF diagnostics in endemic areas where extensive
diagnostic equipment and trained personnel are not available (Algaar et al. 2015).
Yang et al. (2015) developed an Fe 3 O 4 @SiO 2 MP-based CL approach to
detect sequence-specific DNA present in infectious pathogens, by utilizing the CL
system of alkaline phosphatase (AP) and 3-(2
-spiroadamantyl)-4-methoxy-4-(3
-
phosphoryloxy) phenyl-1,2-dioxetane (AMPPD) (Tang et al. 2013; Wang et al.
2012; Li et al. 2011; Yang et al. 2015) (Table 6.1). Due to the poor detection sensitivity resultant from steric hindrance caused by DNA hybridization, the authors used