ABSTRACT
Integrated biochips exploit a multi-disciplinary approach to produce portable point-of-care medical diagnostic systems that uncouple diagnosis from centralized laboratories. These portable devices are cost effective and have several advantages including broader accessibility to health care worldwide. Fluorescence detection of a disease-specific probe excited by an optical source is one of the most diffused methods for quantitative analysis on biochips. Here we designed and characterized a miniaturized biochip based on a novel deep-blue organic light-emitting diode. The molecular design of the diode was optimized to excite a fluorophore-conjugated antibody and tested on a protein microarray configuration with good sensitivity and specificity. These findings will be instrumental for the development of next generation point-of-care biochips.
Subject(s)
Protein Array Analysis/instrumentation , Fluorescence , Fluorescent Dyes/analysis , GTP-Binding Proteins/analysis , Humans , Immunoconjugates/analysis , Light , Point-of-Care Systems , Protein Glutamine gamma Glutamyltransferase 2 , Sensitivity and Specificity , Transglutaminases/analysisABSTRACT
For a lab-on-chip application, we fabricate a blue bottom emitting strong microcavity organic light emitting diode (OLED), using very smooth and optically thin (25 nm) silver film as anode on a glass substrate. To improve the hole injection in the OLED device, PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)) has been used, so the silver anode must present not only a very smooth surface but also a strong adherence on the glass and a high wettability to allow a good PEDOT-PSS spin coating deposition. To obtain these physical properties, different 5 nm thick nucleation layers (germanium, chromium, and hydrogenated amorphous carbon) have been used to grow the silver thin films by e-beam deposition. The Ge/Ag bilayer presents all the desired properties: this bilayer, investigated by ellipsometry, optical profilometry, contact angle measurements, and XPS analysis, highlights an ultrasmooth surface correlated with the film growth mode and a high wettability related to its surface chemical composition.
