We developed Enzyme Coated Nanotubes (ECNT). Miniaturized enzymatic biosensors are in great demand for medical, environmental and chemical analysis. Carbon Nanotubes have a three dimensional network that provide excellent stability, promote enhanced enzyme loading and provide increased analyte exposure. Nanotubes are coated uniformly with an enzyme specific to the desired analyte to provide unsurpassed sensitivity and selectivity. The ECNT electronic tongue concept can analyze a large number of analytes from a single drop of blood, urine or saliva for metabolic analysis. In addition to metabolic sensing, the ECNT electronic nose can perform similar functions for toxic gas detection and chemical warfare sensing.