Abstract
Alzheimer’s disease is a progressive neurodegenerative disease of the brain which is the most common form of age-related dementia. Currently, approximately 17-25 million people worldwide suffer from Alzheimer’s disease, and by the middle of the 21st century, the number of patients with this form of dementia is expected to grow to at least 60 million. Due to that, previous studies have depicted that the beta-amyloid, acetylcholine and glutamate will change abnormally in AD patient brain. Therefore, to fabricate a biosensor for detecting Alzheimer’s disease, especially the amounts of beta-amyloid, acetylcholine and glutamate were is important. In this study, sol-gel array-based optical biosensors for the detection of the Alzheimer’s disease were fabricated by determining of beta-amyloid, glutamate and acetylcholine. The sol-gel array-based optical biosensors were encapsulated with horseradish peroxidase (HRP), glutamate dehydrogenase (GLdh) and acetylcholineasterase (AChE) as biorecognization molecules. By incorporaing amplex red and SNARF-1-dextran into sol-gel matrices, the concentrations of beta-amyloid, glutamate and acetylcholine could be determined using the sol-gel array-based optical biosensor. The detection limits of beta-amyloid, glutamate and acetylcholine were 0.67 □g/ml, 0.53□M and 1.02 □M, respectively. The developed biosensors were also applied to real human serum samples and the detection limits were 1.02 □g/ml to beta-amyloid, 4.5 □M to glutamate and 0.3 □M to acetylcholine, respectively. The array-based biosensors showed good analytical performance with dynamic range of 4-5 orders of magnitude. Results obtained cleanly show that the successful fabrication of sol-gel array-based optical biosensors that has excellent performances on determination of beat-amyloid, acetylcholine and glutamate in the Alzheimer’s disease.