A rapid and sensitive fluorescence method for detecting urine formaldehyde in patients with Alzheimer’s disease

Background: Morning urine formaldehyde (FA) levels could predict the severe degree of dementia in patients with post-stroke dementia (PSD) and Alzheimer’s disease (AD). However, the routinely available technique of high-performance liquid chromatography (HPLC) for detecting urine FA requires expensive and sophisticated equipments. Methods: We established a fluorescence spectrophotometric method by using a FA-specific fluorescent probe- NaFA (λex/em = 430/543 nm). As a standard reference method, the same batch of urine samples was analyzed by HPLC with a fluorescence detector (λex/em = 346/422 nm). Then we compared the limits of detection (LOD) and the limits of quantization (LOQ) detected by these two methods, and addressed the relationship between urine FA and human cognitive ability. The Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) and Activities of Daily Living Scale (ADL) were used to evaluate cognition function in 30 AD patients and 52 healthy age-matched controls.Results: LOD...