Early detection of Alzheimer's disease by measuring amyloid beta-42 concentration in human serum based on liquid crystals

Amyloid beta (Aβ) protein is one of main biomarkers for the diagnosis of Alzheimer's disease (AD). The detection of Aβ in the blood leads to the identification of people prone to AD years before the appearance of the disease. Since the concentration of Aβ in the blood is very low, it is still challenging to detect Aβ using a sensitive, simple and rapid sensor. Herein, we fabricate a new type of liquid crystal-based biosensor to detect Aβ. This sensor is based on the interaction between the negative DNA aptamer and the cationic surfactant called Cetyltrimethylammonium bromide (CTAB). The response time of this setup is about a few minutes and has a good specificity for Aβ in Human Serum (HS). The specific aptamer provided high sensitivity for the sensor with a limit of detection of Aβ as low as 100 pg/ml. The fabricated sensor is inexpensive, easy manufactured and rapid. The proposed system can be a promising strategy for early diagnosis of AD and prevention of side effects of this disease. © 2017 Elsevier Inc. All rights reserved.