Rapid endotoxin entrapment and detection on surface-engineered glass substrates
LPS is captured from an analyte on a long-chain silane-functionalised glass substrate and tagged with gold nanoparticle (GNP) probes, surface-engineered with a narrow-spectrum antibiotic drug -- polymyxin B -- that has high specificity for LPS molecules. The signal sensitivity after GNP binding is further amplified using a 30-second silver reduction step that produces colorimetric spots in the upper femtomolar range but still visible to the naked eye. The color intensity is also quantified using an LED smartphone-based optical acquisition system and a MATLAB image-processing code. The enhancement of net sensitivity of detection beyond the clinical limit to allow pre-symptomatic (subclinical) stage monitoring and screening is performed.
Link: approach is found to be simple, sensitive, robust and cost-effective, suggesting great utility for clinical usage.