Portable paper-based colorimetric nanoprobe for the detection of Stachybotrys chartarum using peptide labeled magnetic nanoparticles

摘要

A colorimetric assay is presented for the detection of Stachybotrys chartarum proteases asbiomarkers. The assay comprises a gold film acting as solid support andcarrying an immobilized peptide substrate that is specific for S. chartarum protease. The substrate was conjugated to black magnetic nanoparticles (MNPs) to form a monolayer on the gold film. Hence, detection nanoprobe is black. If, however, the peptide-MNP fragments are cleaved by S. chartarum proteases present in a sample, the golden color of the detecting nanoprobe becomes apparent so that positive visual readout is enabled. The method was applied to the determination of S. chartarum in (spiked) environmental samples. The limit of detection ranges from 10 to 100 spores mL( -1) depending on the kind of sample (culture, dust, mold and soil). Assay specificity was examined for Aspergillus flavus, Fusarium solani. Penicillin chrysogenum, and Saccharomyces cerevisiae, and negative readouts were observed visually for all samples, except for those also containing S. chartarum.