Gold/Phospholipid nanoconstructs as label-free optical probes for evaluating phospholipase A2 activity
Journal
Biosensors and Bioelectronics
Journal Volume
52
Pages
202-208
ISSN
1873-4235
Date Issued
2014-02-15
Author(s)
Abstract
A facile, monophasic strategy, involving a cooperative solvent, dimethylformamide (DMF), to synthesize core/shell architectured gold-phospholipid hybrid nanoconstructs (PLGNPs) was presented herein. We employed the as-synthesized PLGNPs as enzymatic substrates and detecting probes, leading to the development of a novel, lag time-free quantitative assay to evaluate the activity of Ca2+-dependent phospholipase A2 (PLA2), an inflammatory protein that (i) plays a role in the pathogenesis of many inflammatory diseases, (ii) is a mediator in atherosclerosis and ischemic damage to cardiomyocytes, and (iii) has been implicated in the cause of neurodegenerative diseases. Our new bioassay exhibited high specificity, improved speed (assay time:≤20min), acceptable sensitivity, and a limit of detection (1.82nM, equivalent to 0.04unit/mL and 260ng/dL) below the cut-off value of circulating PLA2 (2.07nM, equivalent to 290ng/dL) present in serum samples collected from healthy testers. We characterized the as-obtained PLGNPs using UV-vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). These PLGNPs were considerably robust and biocompatible-displaying extraordinary stability against salt-induced aggregation, oxidant etching, and repetitive freeze/thaw treatment-because of the presence of their modifying interfacial thiol (1-dodecanethiol) and phospholipid [1,2-dihexadecanoyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol)] units.
Subjects
Gold/phospholipid hybrid nanoconstructs
Label-free optical sensor
One-pot synthesis
Phospholipase A2
Publisher
Elsevier B.V.
Type
journal article