30
K. Sinha et al.
Leo 2005). In addition, the gastrointestinal tract has also been reported for secreting
serotonin to control the intestinal movement (Camilleri 2009). Its abnormal levels
have been related not only with various disorders namely neurodegenerative diseases,
autism, inflammatory syndromes but also linked with a number of psychotic states
including attention-deficit hyperactivity disorder (Carver et al. 2009). In addition,
altered serotonin levels have been reported to be associated with sudden death symptoms of infant and an influence on phenomenon of natural aging (Paterson et al.
2006). This implies that it is highly important to quickly detect serotonin for health
care and clinical treatment. However, serotonin concentration in body fluid is ~15 nM
whereas, in urine it is around 295–687 nM, thus, the detection of serotonin is often
applied by specific techniques that are complicated strategies, high cost, and timeconsuming (Artigas et al. 1985; Huang et al. 2012; Tekes 2008; Umeda et al. 2005).
In this regard, high-quality electrocatalyst-based electrochemical sensor would be a
valuable clinical diagnostic tool to permit the simple, sensitive, accurate, rapid, and
reliable detection of low serotonin levels.
Recently, numerous detection methods have been developed to monitor serotonin, but still several problems exist. For instance, several detection techniques such
as solvent extraction and ion-exchange chromatography require extensive sample
preparation and are aspecific with respect to other indole species (Tonelli et al.
1982). Comparably, this can be overcome by high-performance liquid chromatography (HPLC), which can distinguish between different indoles. Therefore, it is
currently the most common technique in the field, but it is especially costly and
requires sophisticated equipment, making it unsuitable for routine tests (Anderson
1991; Patel et al. 2005; Kema et al. 2000). Hence, another alternative detection system
must be needed to overcome these problems of the conventional serotonin detection
systems.
Recently, a semiconducting nanorod field-effect transistor (FET)-based biosensors have gained much interest owing to its outstanding properties and efficiency. As
sensing elements, the FET device serves to overcome many obstacles faced by current
sensing technologies. For example, significant advantages such as portability, high
sensitivity, fast response, low manufacturing cost, and label-free detection procedure
have provided a clear aspect to develop FET-based biosensors for analyzing biological/chemical molecules. To this end, in this study, zinc oxide nanorod FET device,
was utilized for the first time to develop a highly sensitive biosensor for detecting
serotonin molecule in a fast response manner. Different concentrations of serotonin
molecule (range from 1 fM to 1 μM) in a wide range were sensitively analyzed by
current change based on the immunoreactions.
K. Sinha et al.
Leo 2005). In addition, the gastrointestinal tract has also been reported for secreting
serotonin to control the intestinal movement (Camilleri 2009). Its abnormal levels
have been related not only with various disorders namely neurodegenerative diseases,
autism, inflammatory syndromes but also linked with a number of psychotic states
including attention-deficit hyperactivity disorder (Carver et al. 2009). In addition,
altered serotonin levels have been reported to be associated with sudden death symptoms of infant and an influence on phenomenon of natural aging (Paterson et al.
2006). This implies that it is highly important to quickly detect serotonin for health
care and clinical treatment. However, serotonin concentration in body fluid is ~15 nM
whereas, in urine it is around 295–687 nM, thus, the detection of serotonin is often
applied by specific techniques that are complicated strategies, high cost, and timeconsuming (Artigas et al. 1985; Huang et al. 2012; Tekes 2008; Umeda et al. 2005).
In this regard, high-quality electrocatalyst-based electrochemical sensor would be a
valuable clinical diagnostic tool to permit the simple, sensitive, accurate, rapid, and
reliable detection of low serotonin levels.
Recently, numerous detection methods have been developed to monitor serotonin, but still several problems exist. For instance, several detection techniques such
as solvent extraction and ion-exchange chromatography require extensive sample
preparation and are aspecific with respect to other indole species (Tonelli et al.
1982). Comparably, this can be overcome by high-performance liquid chromatography (HPLC), which can distinguish between different indoles. Therefore, it is
currently the most common technique in the field, but it is especially costly and
requires sophisticated equipment, making it unsuitable for routine tests (Anderson
1991; Patel et al. 2005; Kema et al. 2000). Hence, another alternative detection system
must be needed to overcome these problems of the conventional serotonin detection
systems.
Recently, a semiconducting nanorod field-effect transistor (FET)-based biosensors have gained much interest owing to its outstanding properties and efficiency. As
sensing elements, the FET device serves to overcome many obstacles faced by current
sensing technologies. For example, significant advantages such as portability, high
sensitivity, fast response, low manufacturing cost, and label-free detection procedure
have provided a clear aspect to develop FET-based biosensors for analyzing biological/chemical molecules. To this end, in this study, zinc oxide nanorod FET device,
was utilized for the first time to develop a highly sensitive biosensor for detecting
serotonin molecule in a fast response manner. Different concentrations of serotonin
molecule (range from 1 fM to 1 μM) in a wide range were sensitively analyzed by
current change based on the immunoreactions.