New stochastic microsensors based on oleamides

Fast screening method for early diagnostic of gastric cancer based on utilization of a chitosan - S-doped graphene - based needle stochastic sensors

Needle stochastic sensors were developed for the assay of carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) in different biological samples (e.g., whole blood, tissues, urine, and saliva). Sulfur doped graphene powders were modified with chitosan; paraffin oil was added to form a homogeneous paste that was used as active side of the stochastic sensors. High sensitivities and low limits of determination were achieved for the assay of CA19-9 and CEA in biological samples. The validation of the proposed screening method (which is utilizing the stochastic sensors as screening tools) was made by using real biological samples obtained from confirmed patients with gastric cancer; very good correlations for the concentrations of CEA and CA19-9 were obtained using the needle stochastic sensors.

Stochastic sensors designed for assessment of biomarkers specific to obesity

Two stochastic sensors based on the following oleamides: 1-adamantyloleamide and N,N-dimethyl-N-(2-oleylamidoethyl)amine physically immobilized on graphite paste were designed. The sensors were able to determine simultaneously from the whole blood of Wistar rats three biomarkers specific to obesity: leptin, interleukin-6 (IL-6) and plasminogen activator inhibitor 1 (PAI-1). The whole blood samples were obtained from Wistar rats treated with oleoylethanolamide (OEA), (Z)-N-[(1S)-2-hidroxy-1-(phenylmethyl) ethyl]-9octadecenamide (OLA), and with the aqueous solution of 1% Tween 80 used as solvent for oleamides formulations (control samples). The proposed sensors were very sensitive and reliable for the assay of obesity biomarkers in whole blood of rats.

Pattern recognition of monocyte chemoattractant protein-1 (MCP-1) in whole blood samples using new platforms based on nanostructured materials

Four stochastic microsensors based on nanostructured materials (graphene, maltodextrin (MD), and diamond) integrated in miniaturized platforms were proposed. Monocyte chemoattractant protein-1 (MCP-1) is a pro-inflammatory cytokine whose main function is to regulate cell trafficking. It is correlated with the incidence of cardiovascular diseases and obesity, and was used as the model analyte in this study. The screening of whole blood samples for MCP-1 can be done for concentrations ranging from 10(-12) to 10(-8) g mL(-1). The method was used for both qualitative and quantitative assessments of MCP-1 in whole blood samples. The lowest quantification limits for the assay of MCP-1 (1 pg mL(-1)) were reached when the microsensors based on protoporphyrin IX/Graphene-Au-3 and on MD/Graphene were employed in the platform design.

New nanocomposite-graphene pastes based stochastic microsensors

Stochastic sensors based on metal nanocomposites-graphene pastes modified with protoporphyrin-IX were used for the assay of PPAR-γ in cerebrospinal liquid.