ABSTRACT
A highly sensitive chemiluminescent immunoassay (CLIA) using a sensitive organic photodetector was developed to detect human cortisol, an important biomarker for stress-related diseases. The developed CLIA was performed onto gold-coated glass chips, on which anti-cortisol antibodies were immobilised and chemiluminescent horseradish peroxidase-luminol-peroxide reactions were generated. Using cortisol-spiked artificial saliva samples, the CLIA biosensor showed a linear range of detection between 0.1 ng/mL and 175 ng/mL and a detection limit of 80 pg/mL. The sensor response was highly specific to cortisol and did not vary significantly between assays. The results indicate the potential clinical application of the CLIA sensor. Furthermore, the simple layered structure of the organic photodetector may encourage the realisation of integrated optical biosensors for point-of-use measurement of salivary cortisol levels.
Subject(s)
Biosensing Techniques , Hydrocortisone/metabolism , Immunoassay , Carbazoles/chemistry , Carbodiimides/chemistry , Dimethylamines/chemistry , Electrochemistry , Electronics , Enzyme-Linked Immunosorbent Assay , Equipment Design , Gold/chemistry , Horseradish Peroxidase/chemistry , Humans , Hydrocortisone/analysis , Luminescence , Luminol/chemistry , Peroxides/chemistry , Reproducibility of Results , Saliva, Artificial/metabolismABSTRACT
This work reports on integrated passive-flow optical microfluidic devices to detect waterborne pathogens in the field. Ring-shaped organic photodiodes were integrated to a capillary-induced flow microfluidic channel for monitoring chemiluminescent sandwich immunoassays enhanced by gold nanoparticles. The integrated device yielded a resolution of 4×10(4) cells/mL for the detection of Legionella pneumophila, which represented a 25-fold improvement over chemiluminescence detection devices employing no gold-nanoparticle enhancement. This work demonstrates the feasibility of a low-cost but highly sensitive lab-on-a-chip device amenable for point-of-use applications.
Subject(s)
Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Legionella pneumophila/isolation & purification , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methods , Water Microbiology , Antibodies, Immobilized/immunology , Gold/chemistry , Immunoassay , Lab-On-A-Chip Devices , Legionella pneumophila/immunology , Luminescent Measurements , Metal Nanoparticles/chemistry , Point-of-Care Systems , Polymers/chemistryABSTRACT
UNLABELLED: Diabetes mellitus (DM) is a strong predictor of in-stent restenosis. This may be due to a higher level of vascular inflammation. We hypothesized that diabetic patients will benefit from dexamethasone-eluting stents, since local inflammation and consequently neointimal growth are suppressed and no systemic side effects will occur. METHODS: 21 consecutive patients with DM with 32 lesions were treated with dexamethasone-eluting stents. Excluded were patients with triple vessel disease, bifurcation lesions, previous revascularization of the culprit vessel, and reference diameter smaller than 2.5 or larger than 3.75 mm. MACE (death, myocardial infarction, and revascularization) was counted at 12 months. At 6 months, angiographic follow-up was performed. RESULTS: Of the patients, 38% had insulin-dependent DM. Lesion type was type A/B1 in 56% and B2/C in 44%. Lesion length was 15.7+/-8.4 mm and the reference diameter was 2.83+/-0.53 mm. Event-free survival at 12 months was 62%. Any revascularization procedure was performed in 33% and target lesion revascularization in 24% of the patients. At 6 months in-stent late loss was 1.07+/-0.64 mm. Binary restenosis occurred in 28.1% of the lesions. The event-free survival in insulin-dependent DM was worse compared to non-insulin-dependent DM (92.1 vs. 37.8%; p<0.01). Patients with insulin-dependent DM had higher in-stent late loss compared to non-insulin-dependent DM patients (1.44+/-0.83 vs. 0.83+/-0.51 mm; p<0.01). CONCLUSION: Treatment with dexamethasone-eluting stents in patients with DM is associated with a relatively high restenosis rate. Our data suggest a differential effect of dexamethasone-eluting stents in insulin-dependent compared to non-insulin-dependent DM.
