Patterning substrates with biological reagents is a critical component of biosensor development. Many applications require multi-analyte patterning capabilities, with a need to deposit several species reproducibly with a high degree of precision. We demonstrate a piezoelectric inkjet printing system that is capable of creating sub-millimeter (down to 150microm) patterns of aqueous and nonaqueou...

in this study, the trace amounts of erythrosine, as a food dye is determined by cloud point extraction-scanometry (cpe-scanometry) as a new, facile, available, fast, sensitive, and low cost method. the method is based on the cpe of analyte from aqueous solution, diluting the extracted surfactant-rich phase with ethanol, transfer to plexiglas®cell and scanning the cells containing the analyte so...

Efficient mass transport through porous networks is essential for achieving rapid response times in sensing applications utilizing porous materials. In this work, we show that open-ended porous membranes can overcome diffusion challenges experienced by closed-ended porous materials in a microfluidic environment. A theoretical model including both transport and reaction kinetics is employed to s...

Ekins' ambient analyte theory predicts, counterintuitively, that an immunoassay's limit of detection can be improved by reducing the amount of capture antibody. In addition, it also anticipates that results should be insensitive to the volume of sample as well as the amount of capture antibody added. The objective of this study was to empirically validate all of the performance characteristics ...

The mechanism of volatile hydride generation (HG) and the formation of analyte atoms in the quartz cell atomizer used in the determination of hydride-forming elements (As, Bi, Ge, Pb, Sb, Sn, Te etc.) by atomic absorption spectrometry (AAS), have been critically reviewed. The nascent hydrogen mechanism failed to explain hydride generation under different experimental conditions when tetrahydrob...

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to determine the effect of ambient probe incidence angle on the amount and direction of analyte molecules transported from the sample surface for desorption electrospray ionization (DESI). Incidence angle was critical to both the lateral dispersion and vertical take-off angles of analyte molecules desorbed from the surface; as t...

In environmental epidemiology, measurements of exposure biomarkers often fall below the assay's limit of detection. Existing methods for handling this problem, including deletion, substitution, parametric regression, and multiple imputation, can perform poorly if the proportion of "nondetects" is high or parametric models are mis-specified. We propose an approach that treats the measured analyt...

Using an image-based method for label-free detection of biochemical binding density distribution on the surface of a photonic crystal biosensor mbedded within standard format multiwell microplates, a new method for automatic referencing of assay errors due to variability in the bulk efractive index of the analyte test sample is demonstrated. The new method involves application of the immobilize...

The dependence of analyte sensitivity and vaporization efficiency on the operating parameters of an inductively coupled plasma mass spectrometer (ICPMS) was investigated for a wide range of elements in aerosols, produced by laser ablation of silicate glass. The ion signals were recorded for different carrier gas flow rates at different plasma power for two different laser ablation systems and c...

We report a facile method to design NIR ratiometric fluorescent probes in terms of analyte-induced carbamate cleavage. Two examples, CyNB and CyNN3, exhibit a significant analyte-triggered response with ratiometric fluorescence change in the NIR range and dual-emission ratiometry in living cells.