Abstract: Disclosed is an implantable microspectrometer for the reagentless optical detection of an analyte in a sample fluid. The microspectrometer comprises an optical sampling cell having a cell housing defining a fluid inlet port and a fluid outlet port, the fluid inlet port configured to receive an optical sampling fluid from a test subject; an electromagnetic radiation source in communication with a first portion of the optical sampling cell housing and configured to irradiate at least a portion of the optical sampling fluid with electromagnetic radiation; and an electromagnetic radiation detector in communication with a second portion of the optical sampling cell housing and configured to detect electromagnetic radiation emanating from the optical sampling cell. In use, the implantable microspectrometer can optically detect at least one parameter of an analyte contained within the optical sampling fluid in the absence of an added reagent.

Abstract: A method for generating a net analyte signal calibration model for use in detecting and/or quantifying the amount of an analyte in a test subject. The net analyte signal can be generated by providing a set of in vivo infrared spectra for a test subject during a period in which an analyte concentration is essentially constant; calculating an optimal subspace of spectra that at least substantially describes all non-analyte dependent spectral variance in the in vivo spectra; providing a pure component infrared spectrum for the analyte; and calculating a net analyte signal spectrum from a data set comprising the optimal subspace spectra and the pure analyte spectrum. The net analyte signal calibration model can be used, for example, in measuring the concentration of analyte in a test subject, and/or for evaluating the analytical significance of an in vivo multivariate calibration model.

Abstract: An optical sensor is disclosed which uses a radioluminescent light source to supply the incident radiation for detecting a selected substance in a test medium. The radioluminescent source includes a beta emitting radio isotope which energizes a co-immobilized luminophore to release light in a given wavelength for a chemical sensor operation. The radioluminescent source is coupled with a sensing matrix for detecting and quantifying the analyte of interest. The sensing matrix produces a characteristic signal based on either absorbance or fluorescence which varies according to the concentration of the selected analyte in the sample. A photodetector measures the resulting optical signal from which the analyte concentration is determined.

Abstract: An improved phosphate selective membrane electrode using bis(p-chlorobenzyl)tin dichloride as the membrane active component. In addition to this tin compound, the membrane contains N,N-dimethylformamide (DMF), a strong complexing agent for tin compounds.

Abstract: A novel ion-selective membrane electrode for the determination of phosphate anions. This device possesses an excellent selectivity for phosphate over many common anions such as sulfate, chloride, bromide, iodide, nitrate, and acetate. The unique feature of this electrode is the use of a di-substituted aryl tin compound as the membrane active material. The incorporation of either dibenzyltin dichloride or bis-p-methylbenzyltin dichloride in a plasticized poly(vinyl) chloride membrane results in a selective membrane electrode for phosphate.

Abstract: A bio-selective potentiometric electrode probe for the determination of amino acid concentrations in aqueous liquids comprising an ammonia gas analytical electrode provided at its tip with a closely adjacent thin layer of a fresh animal tissue containing, as a natural constituent thereof, an enzyme effective to catalyze degradation of the specific amino acid in analysis to either ammonia or to an intermediate compound subject to further degradation to ammonia by an additional enzyme, which ammonia is a function of the amino acid concentration in the liquid.