Clinically accurate diagnosis of Alzheimer’s disease via multiplexed sensing of core biomarkers in human plasma

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder, affecting one in ten people aged over 65 years. Despite the severity of the disease, early diagnosis of AD is still challenging due to the low accuracy or high cost of neuropsychological tests and neuroimaging. Here we report clinically accurate and ultrasensitive detection of multiple AD core biomarkers (t-tau, p-tau181, Aβ42, and Aβ40) in human plasma using densely aligned carbon nanotubes (CNTs). The closely packed and unidirectionally aligned CNT sensor array exhibits high precision, sensitivity, and accuracy, evidenced by a low coefficient of variation (<6%), a femtomolar-level limit of detection, and a high degree of recovery (>93.0%). By measuring the levels of t-tau/Aβ42, p-tau181/Aβ42, and Aβ42/Aβ40 in clinical blood samples, the sensor array successfully discriminates the clinically diagnosed AD patients from healthy controls with an average sensitivity of 90.0%, a selectivity of 90.0%, and an average accuracy of 88.6%.


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nature research | reporting summary
October 2018

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The sample size for each experiment is indicated in the figure legend. No sample-size calculations were performed. The sample size was determined to be adequate based on the magnitude and consistency of measurable differences between groups.
From 45 plasma samples, five outliers were excluded from the analyses because the concentration of biomarkers in the samples deviated from the measurable ranges with standard curves.
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The participants were aged 65 to 81 years. The plasma samples tested were a total of 45. The samples of Alzheimer's patients tested consisted of 10 males and 11 females (21 in total). The samples of healthy individuals tested consisted of 14 males and 10 females (24 in total).