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Y. Cheng and H. Jin
probe, thus releasing the probe from the GO surface and the fluorescence is restored.
The hCG concentration can be detected according to the fluorescence intensity and
the detection limit was found to be 20 mIU/mL. This detecting system has been
applied to urine samples as a promising application for portable hCG diagnosis of
pregnancy.
11.3.2 Application of Aptamer in Real-Time Detection
The human inner environment and numerous biochemical interactions are complex;
it is essential to find out an approach to detect the concentration of substances in the
human body continuously and simultaneously. Real-time detection renders us to have
a deeper understanding of the human’s physical status, which can make it to precision
medicine and enable clinicians to tailor personalized treatments for different patients.
Such monitoring methods can help tackle a series of diseases as well. However, it is
still difficult for scientists to continuously and simultaneously detect biomolecules
in vivo. In recent years, scientists have been trying to develop innovative clinical
diagnostic systems, e.g., transforming mobile phones into potential diagnostic tools.
For traditional detecting systems, the complicated procedural measures and
continuous drug administering under the development of real-time detection to a
large extent [71]. For conventional detection methods such as chromatography, mass
spectrometry, and immunochemistry, continuous detection cannot be achieved due to
the complexity of their tedious sample processing steps, analyte washing/separation
steps, and sequential addition of reagents. As for some biosensors, like biosensors
based on surface plasmon resonance (SPR) [72] or field-effect transistors (FET),
they normally cannot stably exist in the blood, and cannot well distinguish specific
binding and non-specific adsorption of targets, so they cannot easily achieve real
time monitoring in vivo [73]. In the past, scientists believed that real-time detection
mainly depended on specific chemical reactions of the target, such as redox reactions of the target. According to the specific target redox reaction and its reaction with
certain enzymes in the body, scientists have been able to monitor glucose [74], lactic
acid [75], dopamine [76], serotonin [77], and glutamate [78] continuously in real
time. Unfortunately, this merit does not apply to many other important substances
in the body. Due to the superior specificity and sensitivity of the aptamer in binding
with the target, scientists decide to construct aptamer-based sensors for continuous
real-time monitoring. The most important element of the aptasensor is the aptamer
probe, which can be attached to the electrode. In an aptamer-based electrochemical
sensor system, the modified aptamer probe is fixed to the electrode. When the aptamer
combines with the target in different concentration window [79–81], corresponding
conformational or adaptability changes will be produced, which can be detected
by electrochemical method. When square wave voltammetry is used for measurement, the sensor system will show current change depending on the concentration,
so as to realize the purpose of real-time monitoring [82]. Scientists have managed to
fabricate aptasensors for real-time detection of various aminoglycoside antibiotics
Y. Cheng and H. Jin
probe, thus releasing the probe from the GO surface and the fluorescence is restored.
The hCG concentration can be detected according to the fluorescence intensity and
the detection limit was found to be 20 mIU/mL. This detecting system has been
applied to urine samples as a promising application for portable hCG diagnosis of
pregnancy.
11.3.2 Application of Aptamer in Real-Time Detection
The human inner environment and numerous biochemical interactions are complex;
it is essential to find out an approach to detect the concentration of substances in the
human body continuously and simultaneously. Real-time detection renders us to have
a deeper understanding of the human’s physical status, which can make it to precision
medicine and enable clinicians to tailor personalized treatments for different patients.
Such monitoring methods can help tackle a series of diseases as well. However, it is
still difficult for scientists to continuously and simultaneously detect biomolecules
in vivo. In recent years, scientists have been trying to develop innovative clinical
diagnostic systems, e.g., transforming mobile phones into potential diagnostic tools.
For traditional detecting systems, the complicated procedural measures and
continuous drug administering under the development of real-time detection to a
large extent [71]. For conventional detection methods such as chromatography, mass
spectrometry, and immunochemistry, continuous detection cannot be achieved due to
the complexity of their tedious sample processing steps, analyte washing/separation
steps, and sequential addition of reagents. As for some biosensors, like biosensors
based on surface plasmon resonance (SPR) [72] or field-effect transistors (FET),
they normally cannot stably exist in the blood, and cannot well distinguish specific
binding and non-specific adsorption of targets, so they cannot easily achieve real
time monitoring in vivo [73]. In the past, scientists believed that real-time detection
mainly depended on specific chemical reactions of the target, such as redox reactions of the target. According to the specific target redox reaction and its reaction with
certain enzymes in the body, scientists have been able to monitor glucose [74], lactic
acid [75], dopamine [76], serotonin [77], and glutamate [78] continuously in real
time. Unfortunately, this merit does not apply to many other important substances
in the body. Due to the superior specificity and sensitivity of the aptamer in binding
with the target, scientists decide to construct aptamer-based sensors for continuous
real-time monitoring. The most important element of the aptasensor is the aptamer
probe, which can be attached to the electrode. In an aptamer-based electrochemical
sensor system, the modified aptamer probe is fixed to the electrode. When the aptamer
combines with the target in different concentration window [79–81], corresponding
conformational or adaptability changes will be produced, which can be detected
by electrochemical method. When square wave voltammetry is used for measurement, the sensor system will show current change depending on the concentration,
so as to realize the purpose of real-time monitoring [82]. Scientists have managed to
fabricate aptasensors for real-time detection of various aminoglycoside antibiotics