TY - JOUR
T1 - Highly sensitive quantification of alzheimer’s disease biomarkers by aptamer-assisted amplification
AU - Chan, Hei-Nga
AU - Xu, Di
AU - Ho, See-Lok
AU - He, Dinggeng
AU - Wong, Man-Shing
AU - Li, Hung-Wing
N1 - Funding Information:
This work is supported by the Collaborative Research Fund Scheme of the Hong Kong Research Grant Council (C2012-15G).
PY - 2019/5/9
Y1 - 2019/5/9
N2 - Alzheimer’s disease (AD), a chronic neurodegenerative disease associated with the loss of neurons in the brain, is the most pervasive type of dementia; 47 million people are affected, and the number is expected to increase to more than 131 million by 2050, according to Alzheimer’s Disease International. Both early diagnosis and continuous monitoring are crucial for early intervention, symptomatic treatment, monitoring of the efficacy of intervention and improved patient function. Beta-amyloid peptide, tau, and phosphorylated tau are useful for screening and diagnosis; meanwhile, simultaneous assessment of multiple biomarkers is of paramount importance for accurate disease diagnosis. Methods: Herein, we report a direct, inexpensive and ultrasensitive aptamer-based multiplex assay for the quantification of trace amounts of AD biomarkers in both human serum and cerebrospinal fluid (CSF) samples. In this newly developed assay, molecular recognition of an antibody-aptamer pair provides high specificity in target detection, and the use of a DNA amplification strategy affords high sensitivity, allowing quantification of AD biomarkers in both biological fluids in 1.5 h with only a diminutive amount of the sample consumed. A tailor-made turn-on fluorophore, namely, SPOH, was employed to label the antibody-aptamer hybrids and provide a strong fluorescence signal, which was then detected with a total internal reflection fluorescence microscopy electron-multiplying charge-coupled device (TIRFM-EMCCD) imaging system. The simultaneous detection of biomarkers was achieved by a direct shape-coded method in which the nanoplatforms can be distinguished from one another by their morphologies. Results: This assay demonstrated a lower detection limit (in the femtomolar range) for AD biomarkers than the previously reported antibody-antibody method. Conclusion: The developed assay holds tremendous clinical potential for early diagnosis of AD and monitoring of its progression.
AB - Alzheimer’s disease (AD), a chronic neurodegenerative disease associated with the loss of neurons in the brain, is the most pervasive type of dementia; 47 million people are affected, and the number is expected to increase to more than 131 million by 2050, according to Alzheimer’s Disease International. Both early diagnosis and continuous monitoring are crucial for early intervention, symptomatic treatment, monitoring of the efficacy of intervention and improved patient function. Beta-amyloid peptide, tau, and phosphorylated tau are useful for screening and diagnosis; meanwhile, simultaneous assessment of multiple biomarkers is of paramount importance for accurate disease diagnosis. Methods: Herein, we report a direct, inexpensive and ultrasensitive aptamer-based multiplex assay for the quantification of trace amounts of AD biomarkers in both human serum and cerebrospinal fluid (CSF) samples. In this newly developed assay, molecular recognition of an antibody-aptamer pair provides high specificity in target detection, and the use of a DNA amplification strategy affords high sensitivity, allowing quantification of AD biomarkers in both biological fluids in 1.5 h with only a diminutive amount of the sample consumed. A tailor-made turn-on fluorophore, namely, SPOH, was employed to label the antibody-aptamer hybrids and provide a strong fluorescence signal, which was then detected with a total internal reflection fluorescence microscopy electron-multiplying charge-coupled device (TIRFM-EMCCD) imaging system. The simultaneous detection of biomarkers was achieved by a direct shape-coded method in which the nanoplatforms can be distinguished from one another by their morphologies. Results: This assay demonstrated a lower detection limit (in the femtomolar range) for AD biomarkers than the previously reported antibody-antibody method. Conclusion: The developed assay holds tremendous clinical potential for early diagnosis of AD and monitoring of its progression.
KW - Alzheimer’s disease
KW - Antibody-aptamer hybrid immunoassay
KW - Magnetic nanoparticle
KW - Turn-on fluorophore
UR - http://www.scopus.com/inward/record.url?scp=85066113437&partnerID=8YFLogxK
U2 - 10.7150/thno.29232
DO - 10.7150/thno.29232
M3 - Journal article
C2 - 31244934
AN - SCOPUS:85066113437
SN - 1838-7640
VL - 9
SP - 2939
EP - 2949
JO - Theranostics
JF - Theranostics
IS - 10
ER -
