A porous silicon immunoassay platform for fluorometric determination of α-synuclein in human cerebrospinal fluid

Abstract

Levels of total and/or oligomeric α-synuclein may be used as a biomarker tool to aid in the diagnosis and development of new disease-modifying therapies. We report here on a porous silicon antibody microarray for the fluorimetric determination of cerebrospinal fluid levels of total α-synuclein, a protein involved the pathology of Parkinson’s disease. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, and this offers a large binding capacity for capturing probe molecules. Porous silicon also warrants efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. The platform requires 10 μL of cerebrospinal fluid, and each test requires 4 h for assay only (including immobilization of capturing antibody). The limit of detection is 35 pg mL−1 of α-synuclein in cerebrospinal fluid, and the dynamic analytical range extends from 0.01 to 100 ng·mL−1.