Lateral flow immunoassay with peptide-functionalized gold nanoparticles for rapid detection of protein tyrosine phosphatase 1B

In this work, a lateral flow immunoassay (LFIA) with peptide functionalized gold nanoparticles (termed as biotin-ppeptide-AuNPs) has been developed for rapid, semi-quantitative detection of PTP1B activity without using any sophisticated equipment. In this method, the anti-phosphotyrosine (anti-pY) monoclonal antibody and streptavidin were used as test line and control line, respectively. The biotin-ppeptide-AuNPs contain 10% biotinylated peptide ligand carry a motif SDGHEpYIYVDP with pY (phosphotyrosine) and 90% pentapeptide (CALNN) ligand, which are used as PTP1B substrates and LFIA labelling probes. The experimental results demonstrate that the as-proposed LFIA with biotin-ppeptide-AuNPs exhibits a wide linear range (from 50 ng/mL to 10 mu g/mL), a relatively low limit of detection (LOD, 44 ng/mL), and good specificity. In addition, the LFIA with biotin-(p)peptide-AuNPs has been successfully used to evaluate activity levels of PTP1B in four cell lysates and the detection results exhibit a consistent trend with that of commercial kit.