A cost-effective aptasensor capable of early diagnosis and monitoring of Alzheimer's disease with the rapid analysis of beta-amyloid peptide 1–40

Abstract

A cost-effective biosensor with guanine chemiluminescence detection capable of sensing trace levels of beta-amyloid peptide 1–40 was developed for the early diagnosis and accurate monitoring of Alzheimer's disease (AD), which is the biggest cause of dementia-related memory loss, and other cognitive abilities. A specific DNA aptamer binds rapidly with beta-amyloid peptide 1–40 within 1 hour at room temperature. Free DNA aptamers remaining after the procedure to capture beta-amyloid peptide 1–40 in a sample electrostatically bind with luminescent dye within 5 min at room temperature. After the procedure, 3-methoxylphenylglyoxal hydrate in dimethyl furan and tetra-n-propylammonium hydroxide in deionized water were added to the solution to generate green chemiluminescence. Bright chemiluminescence, created by the internal chemiluminescence resonance energy transfer (inter-CRET) of the luminescent dye bound with the DNA aptamer and the high-energy intermediate formed in guanine chemiluminescence, was measured immediately for 20 s. The relative CL intensity decreased proportionally with the increase of the beta-amyloid peptide 1–40. The limit of detection (LOD) of the biosensor having a wide linear dynamic range (5–500 ng ml⁻¹) was as low as 2 ng ml⁻¹. In addition, it was confirmed that the biosensor can quantify beta-amyloid peptide 1–40 with good accuracy, precision, recovery, and selectivity. We expect the principle and concepts confirmed here to be developed to be applied as a new method capable of early diagnosis and prognosis of human diseases with good reliability.