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Automated-immunosensor with centrifugal fluid valves for salivary cortisol measurement.

Yamaguchi M, Katagata H, Tezuka Y, Niwa D, Shetty V - Sens Biosensing Res (2014)

Bottom Line: Incorporated centrifugal fluid valves allow for rapid and repeat washings to remove impurities from the saliva samples.An optical reader and laptop computer automate the immunoassay processes and provide easily accessible digital readouts of salivary cortisol measurements.The receiver operating characteristic (ROC) curve analysis of human saliva samples indicate potential utility for discriminating stress disorders and underscore potential application of the biosensor in stress disorders.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Engineering & Robotics Laboratory, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.

ABSTRACT

Point-of-care measurement of the stress hormone cortisol will greatly facilitate the timely diagnosis and management of stress-related disorders. We describe an automated salivary cortisol immunosensor, incorporating centrifugal fluid valves and a disposable disc-chip that allows for truncated reporting of cortisol levels (<15 min). The performance characteristics of the immunosensor are optimized through select blocking agents to prevent the non-specific adsorption of proteins; immunoglobulin G (IgG) polymer for the pad and milk protein for the reservoirs and the flow channels. Incorporated centrifugal fluid valves allow for rapid and repeat washings to remove impurities from the saliva samples. An optical reader and laptop computer automate the immunoassay processes and provide easily accessible digital readouts of salivary cortisol measurements. Linear regression analysis of the calibration curve for the cortisol immunosensor showed 0.92 of coefficient of multiple determination, R (2), and 38.7% of coefficient of variation, CV, for a range of salivary cortisol concentrations between 0.4 and 11.3 ng/mL. The receiver operating characteristic (ROC) curve analysis of human saliva samples indicate potential utility for discriminating stress disorders and underscore potential application of the biosensor in stress disorders. The performance of our salivary cortisol immunosensor approaches laboratory based tests and allows noninvasive, quantitative, and automated analysis of human salivary cortisol levels with reporting times compatible with point-of-care applications.

No MeSH data available.


Related in: MedlinePlus

Comparison of the intensities between the nine combinations of blocking agents (B: BSA-PBS-T, M: milk protein, I: IgG polymer).
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Figure 5: Comparison of the intensities between the nine combinations of blocking agents (B: BSA-PBS-T, M: milk protein, I: IgG polymer).

Mentions: Fig. 5 shows the measured intensity results using the standard cortisol solutions. The symbols show a combination of blocking agents for the pad and the disc-chip including the reservoirs and the flow channels (Type pad-disc). The intensities of Type B-B (the pad was blocked with BSA and the disc-chip was blocked with BSA) at concentrations of 1 and 3 ng/mL were 94,732 ± 6,738 and 51,902 ± 3,901 respectively and the absolute difference, ΔI, was 42,830. The intensities of Type I-B at concentrations of 1 and 3 ng/m were 135,293 ± 26,864 and 84,146 ± 10,601, respectively and the absolute difference was 51,147. The intensities of Type I-M concentrations of 1 and 3 ng/mL were 124,179 ± 18,579 and 69,091 ± 6,846, respectively and the absolute difference was 55,089. The difference between the intensities for Type I-M is 1.3 times larger than that for Type B-B.


Automated-immunosensor with centrifugal fluid valves for salivary cortisol measurement.

Yamaguchi M, Katagata H, Tezuka Y, Niwa D, Shetty V - Sens Biosensing Res (2014)

Comparison of the intensities between the nine combinations of blocking agents (B: BSA-PBS-T, M: milk protein, I: IgG polymer).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631318&req=5

Figure 5: Comparison of the intensities between the nine combinations of blocking agents (B: BSA-PBS-T, M: milk protein, I: IgG polymer).
Mentions: Fig. 5 shows the measured intensity results using the standard cortisol solutions. The symbols show a combination of blocking agents for the pad and the disc-chip including the reservoirs and the flow channels (Type pad-disc). The intensities of Type B-B (the pad was blocked with BSA and the disc-chip was blocked with BSA) at concentrations of 1 and 3 ng/mL were 94,732 ± 6,738 and 51,902 ± 3,901 respectively and the absolute difference, ΔI, was 42,830. The intensities of Type I-B at concentrations of 1 and 3 ng/m were 135,293 ± 26,864 and 84,146 ± 10,601, respectively and the absolute difference was 51,147. The intensities of Type I-M concentrations of 1 and 3 ng/mL were 124,179 ± 18,579 and 69,091 ± 6,846, respectively and the absolute difference was 55,089. The difference between the intensities for Type I-M is 1.3 times larger than that for Type B-B.

Bottom Line: Incorporated centrifugal fluid valves allow for rapid and repeat washings to remove impurities from the saliva samples.An optical reader and laptop computer automate the immunoassay processes and provide easily accessible digital readouts of salivary cortisol measurements.The receiver operating characteristic (ROC) curve analysis of human saliva samples indicate potential utility for discriminating stress disorders and underscore potential application of the biosensor in stress disorders.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Engineering & Robotics Laboratory, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.

ABSTRACT

Point-of-care measurement of the stress hormone cortisol will greatly facilitate the timely diagnosis and management of stress-related disorders. We describe an automated salivary cortisol immunosensor, incorporating centrifugal fluid valves and a disposable disc-chip that allows for truncated reporting of cortisol levels (<15 min). The performance characteristics of the immunosensor are optimized through select blocking agents to prevent the non-specific adsorption of proteins; immunoglobulin G (IgG) polymer for the pad and milk protein for the reservoirs and the flow channels. Incorporated centrifugal fluid valves allow for rapid and repeat washings to remove impurities from the saliva samples. An optical reader and laptop computer automate the immunoassay processes and provide easily accessible digital readouts of salivary cortisol measurements. Linear regression analysis of the calibration curve for the cortisol immunosensor showed 0.92 of coefficient of multiple determination, R (2), and 38.7% of coefficient of variation, CV, for a range of salivary cortisol concentrations between 0.4 and 11.3 ng/mL. The receiver operating characteristic (ROC) curve analysis of human saliva samples indicate potential utility for discriminating stress disorders and underscore potential application of the biosensor in stress disorders. The performance of our salivary cortisol immunosensor approaches laboratory based tests and allows noninvasive, quantitative, and automated analysis of human salivary cortisol levels with reporting times compatible with point-of-care applications.

No MeSH data available.


Related in: MedlinePlus