DETECHIP ® is a novel, highly selective and sensitive molecular sensor array producing color and fluorescence changes in the presence of many small molecules or analytes. This technology utilizes an array of eight sensors in two types of buffers that are dispensed in a 96-well plate. Color and fluorescent changes in the presence of analytes are recorded as a 32 digit binary code that is able to discriminate many substances. The current application is dedicated to testing narcotics such as cocaine, tetrahydrocannabinol (THC) from marijuana, as well as daterape and club drugs such as flunitrazepam, gamma-hydroxybutyric acid (GHB), and methamphetamine, to name a few. Shown to be a contactless, portable, and inexpensive optical detection system, DETECHIP ® can detect many substances and therefore can be used where a high degree of preliminary diagnostics is needed.Besides narcotics, DETECHIP ® is able to detect and discriminate over-the-counter medications, trinitrotoluene (TNT), pesticides, food spoilage metabolites, and narcotics laced with cutting agents. DETECHIP ® offers possibilities for a simple, sensitive, selective, and affordable alternative to costly immunoassays.

DETECHIP® is a molecular sensing array used for identification of a large variety of substances. Previous methodology for the analysis of DETECHIP® used human vision to distinguish color changes induced by the presence of the analyte of interest. This paper describes several analysis techniques using digital images of DETECHIP®. Both a digital camera and flatbed desktop photo scanner were used to obtain Jpeg images. Color information within these digital images was obtained through the measurement of red-green-blue (RGB) values using software such as GIMP, Photoshop and ImageJ. Several different techniques were used to evaluate these color changes. It was determined that the flatbed scanner produced in the clearest and more reproducible images. Furthermore, codes obtained using a macro written for use within ImageJ showed improved consistency versus pervious methods.

SummaryWe explored the potentials of microarray printing using quill-like microcantilevers onto solid supports that are typically used in microspot printing, including paper, polymeric nitrocellulose and nylon membranes. We compared these membranes with a novel porous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) support (HEMA) with narrow pore size distribution in the 150 nm range, which demonstrated advantages in pattern definition, spot homogeneity, and consistent spot delivery of different dyes (phloxine B and bromophenol blue) with diameters of several micrometres. The bromophenol blue arrays on HEMA support were used to detect the presence of bovine serum albumin (BSA). In the presence of BSA, the fluorescence spectrum observed from the bromophenol blue microarray exhibited a significant red shift of the maximum emission wavelength. Our results show that the porous HEMA substrates can improve the fidelity and quality of microarrays prepared by using the quill-like microcantilevers. The presented method sets the stage for further studies using chemical and biochemical recognition elements, along with colorimetric and fluorometric sensors that can be spotted by this method onto flat porous polymer substrates.

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