Interactions between peptides and lipid membranes play major roles in numerous physiological processes, such as signaling, cytolysis, formation of ion channels, and cellular recognition. We describe a new colorimetric technique for studying peptide-membrane interactions. The new assay is based on supramolecular assemblies composed of phospholipids embedded in a matrix of polydiacetylene (PDA) m...

For applications where colorimetric information is insufficient to characterize an input scene or document, multispectral image capture (i.e. for more than three records) has been suggested. Experimental cameras have been described, as have the results of signal processing to extract useful spectral and colorimetric information. Previous reports have addressed both system accuracy and precision...

This study describes a modified colorimetric assay for uricase activity in flexible 96-well microtiter plates using the uricase/uric acid/horseradish peroxidase/4-aminoantipyrine/3,5-dichloro-2-hydroxybenzene sulfonate colorimetric reaction. The utility of this assay was demonstrated in a screen for mutant uricase enzymes derived from the uricase gene of the thermophilic bacterium Bacillus subt...

Specific fluorescent profiles were created by loading quantum-dot (Qdot) mixtures in liquid cores of monodispersed polymer microcapsules, which were used as colorimetric barcodes for small object identification. Since the emission intensities of Qdot-loaded liquid cores maintain a linear relation to the Qdot concentrations and the Qdots in the liquid cores with different emission peaks have no ...

Tumor markers are substances, usually proteins, produced by the body in response to cancer growth, or by the cancer tissue itself. They can be detected in blood, urine, or tissue samples, and the discovery and detection of tumor markers may provide earlier diagnosis of cancer and improved therapeutic intervention. Colorimetric immunoassays for tumor marker detection have attracted considerable ...

We present a novel reflectance-based colorimetric aptasensor using gold nanoparticles for the detection of oxytetracycline for the first time. It was found that the reflectance-based measurement at two wavelengths (650 and 520 nm) can generate more stable and sensitive signals than absorbance-based sensors to determine the aggregation of AuNPs, even at high AuNP concentrations. One of the most ...

We describe applications of a colorimetric assay based on supramolecular assemblies of lipid-polydiacetylene vesicles for analysis and screening of membrane interactions of lipophilic enzymes, peptides, and ions and for study of the effects of lipid composition upon membrane properties. The lipid-polymer aggregates undergo visible and quantifiable blue-to-red transitions following interfacial i...

Carbohydrate molecules are involved in many of the cellular processes that are important for life. By combining the specific analyte targeting of carbohydrates with the multivalent structure and change of solution colour as a consequence of plasmonic interactions with the aggregation of metal nanoparticles, glyconanoparticles have been used extensively for the development of bioanalytical assay...

This study proposes a vision model for individual colorimetric observers. The proposed model can be beneficial in many color-critical applications such as color grading and soft proofing to assess ranges of color matches instead of a single average match. We extended the CIE 2006 physiological observer by adding eight additional physiological parameters to model individual color-normal observer...

In the past few years there has been renewed interest in the study of serum cholinesterase in various disease states, particularly those affecting the liver. Recently, a colorimetric method for the determination of this enzyme in the serum was reported by Ravin, Tsou, and Seligman (1). Their method, simple to perform, is as accurate as the gastrometric technique and more specific than the elect...