Immobilization of human immunoglobuline (IgG) (AG) and goat on human IGG antibodies (AB) as well as AB/AG specific reaction were studied with planar polarization interferometry (PPI). In this novel method, polarized laser beam was coupled into the planar waveguide made on silicon wafer and consisted of 20nm Si₃N₄ layer sandwiched between two 1.5 micrometers SiO₂ layers with the sensing window etched in the top SIO₂ layer. One of the immune components was deposited by means of polyelectrolyte self- assembly on top of the Si₃N₃ layer within the sensing window, P-component of the polarized light is sensitive to adsorption, while s-component serves as a reference. Thus the outcoming light intensity depends on the phase shift between s- and p-components. Different sequences of immobilization of the immune components were studied with both surface plasmon resonance (SPR) and PPI methods. It was shown that predeposition of a monolayer of protein A, which is believed to affect the orientation of the immune components, causes an additional increase in the sensitivity. PPI method allowed us to improve substantially the sensitivity towards AB/AG reaction as compared to traditional SPR method. Particularly, of specific binding of 3ng/ml AG was registered.

With the proliferation of biological weapons, the outbreak of food poisoning occurrences, and the spread of antibiotic resistant strains of pathogenic bacteria, the demand has arisen for portable systems capable of rapid, specific, and quantitative target detection. The ability to detect minute quantities of targets will provide the means to quickly assess a health hazardous situation so that the appropriate response can be orchestrated. Conventional test results generally require hours or even several days to be reported, and there is no change for real-time feedback. An interferometric optical fiber microcantilever beam biosensor has successfully demonstrated real time detection of target molecules. The microcantilever biosensor effectively combines advanced technology from silicon micromachining, optical fiber sensor, and biochemistry to create a novel detection device. This approach utilizes affinity coatings on micromachiend cantilever beams to attract target molecules. The presence of the target molecule causes bending in the cantilever beam, which is monitored using an optical displacement system. Dose-response trials have shown measured responses at nanogram/ml concentrations of target molecules. Sensitivity is expected to extend from the nanogram to the picogram range of total captured mass as the microcantilever sensors are optimized.

Polymerization in water hydroperoxide monomer 2-hydroperoxy- 2-methylhexene-5-yne-3 (HM): CH₂equalsCH-CequalsC-C(CH₃)₂-OOH the monodispersible latexes containing on a surface hydroperoxide groups are obtained. The size and particle size distribution is regulated by the initial concentration of a monomer and temperature of course of the process. The microspheres represent cross-linked polymer.

A graded height flow cell was used to measure the adhesion properties of the neural cell line of neuroblastoma X glioma (NG108-15) cells cultured on substrates of organosilane self-assembled monolayers (SAMs). The SAMs tested in this study were 13F, 15F, PEG 550, OTS, DETA and APTS. Utilizing deep UV lithography, patterning of the SAMs create three regions for cell attachment; the original SAM, the backfilled SAM, and the interface between the two. Upon plating, the cell soma show no preference for any of the three regions. One exception was on PEG 550, which was found to resist cell adhesion upon normal plating conditions. The cell processes of the NG108-15 cells show a preference for growth at the interface between two patterned surfaces. A factor of three increase in adhesion properties was found for the patterned surface over an uncoated glass surface. Design rules of a single whole cell biosensor using theNG108-15 cells can be developed based on these findings.

Composite films containing enzyme and indicator molecules were produced by means of polyelectrolyte self-assembly. These membranes provide two functions: (i) molecular recognition of the substratum by respective enzyme, and (ii) optrode transducing, when the products o the substratum decomposition affect optical spectra of indicator molecules. Apart from direct registration of enzyme reactions, inhibition reactions can also be monitored with this method. Particularly, heavy metal salts and phosphor organic pesticides acting as inhibitors for Urease and Cholinesterase, respectively, were registered. Composite PESA films were deposited onto glass slides and consisted of several layers of poly(alylamine) hydrochloride (PAA) alternated with indicator molecules, either Cyclo-tetra- chromotropylene or Thymol Blue, both containing SO₃- Na⁺ groups. Then a few layers of PAA/enzyme were deposited on top. A typical structure of the samples was (PAA/Indicator)_n/(PAA/Enzyme)_m/PAA with n equals 1-5. The obtained films were characterized with UV-visible absorption spectroscopy. The effect of the substrate decomposition on the UV-vis spectra of respective indicator molecules was studied. The inhibition of enzymes Urease and Cholinesterase by heavy metal ions and phosphor organic pesticide, respectively was found. The results obtained show the prospects towards development of optical enzyme sensor arrays.

In the given work the algorithm of work and structure of microchip construction, intended for kinetics researches of formation of modular complexes is considered during the reaction of latex agglutination. The physical principles of registration of enzyme adsorption isotherms on latex by method of light scattering are considered. The result of the reaction of adsorption of protacrin enzyme on hydro peroxide latex's are shown.

Solid phase synthesis, especially spot-synthesis on cellulose membranes is well established for facile preparation of large arrays of biomolecules, e.g. peptides, nucleic acids, peptoides and the subsequent solid and solution phase, screening. Despite many good properties of cellulose membranes for some applications this material has a number of limitations such as low chemical and mechanical stability and high concentration of reactive, chemical different hydroxyl groups causing side reactions. Therefore a novel continuous polymeric material, porous membranes and non-porous materials, was developed based on the chemical and photochemical surface functionalization by grafting of flexible polymer chains carrying the functional and reactive groups for the syntheses. Several classes of compounds e.g. peptides, nucleic acids, peptoides, glucoconjugates and small organic molecules were synthesized using the new continuous polymeric surface.

The fluorescence of fluorescently tagged proteins on functionalized polymer surfaces shifts towards higher wavelengths. Two types of polymers for light-assisted surface manipulation have been used, namely diazo-naphto- quionone/novolak (DNQ/N) resist and poly)tert-butyl- methacrylate). The proteins were either hydrophobicity- attached; covalently linked; or specific protein-protein recognition. We observed that on hydrophilic surfaces the fluorescence is shifted towards lower wavelengths. This parasitic effect has to be taken into account when 'reading' biochips but it can be also used for the 'alignment' of the fluorescence of the fluorescently tagged proteins on the same wavelengths via the manipulation of the properties of the substrate polymer.

There is a growing need for portable, lightweight, battery operated instruments capable of detecting and identifying bio-warfare and bio-terrorism agents in the field. To address this need, we have developed a handheld PCR instrument. LLNLs advanced thermal cycling technology and expertise with portable, field tested biological instrumentation, combined with the development of real-time, fluorescence based PCR assays, has enabled the development of a very portable, versatile, power efficient PCR instrument with a simplified operating system designed for use by first responders. The heart of the instrument is the sample module, which incorporates the advanced silicon thermal cycler developed at LLNL.

We have developed and delivered a four chamber, battery powered, handheld instrument referred to as the HANAA which monitors the polymerase chain reaction (PCR) process using a TaqMan based fluorescence assay. The detection system differs form standard configurations in two essential ways. First, the size is miniaturized, with a combined cycling and optics plug-in module for a duplex assay begin about the size of a small box of matches. Second, the detection/analysis system is designed to call a positive sample in real time.

Field-portable sensor system are currently needed for the detection and characterization of biological pathogens in the environment. Nucleic acid analysis is frequently the method of choice for discriminating between pathogenic and non-pathogenic bacteria in environmental samples, however standard protocols are difficult to automate and current microfluidic devices are not configured to analyze environmental samples. In this paper, we describe an automated DNA sample processing system and demonstrate its use for the extraction of bacterial DNA form water and sediment samples. Two challenges in environmental sample analysis are the need to process relatively large sample volumes in order to obtain detectable quantities of DNA present at low concentrations, and the need to purify DNA form a complex sample matrix for downstream detection. These problems are addressed by using sequential injection fluid handling techniques for precise manipulation of the required volumes, and renewable separation columns for automatically trapping and releasing microparticles that are used for sample purification. The renewable microcolumns are used for both bacterial cell concentration and DNA purification. The purified bacterial DNA is then amplified using an on-line PCR module in order to produce detectable quantities of the target DNA.

The optic properties of human tissues are described. The results of investigating the spectrophotometric characteristics of normal tissues, benign and malignant neoplasms are expounded.

Drug overdose involves more than 10 percent of emergency room (ER) cases, and a method to rapidly identify and quantify the abused drug is critical to the ability of the ER physician to administer the appropriate care. To this end, we have been developing a surface-enhanced Raman (SER) active material capable of detecting target drugs at physiological concentrations in urine. The SER-active material consists of a metal-doped sol-gel that provides not only a million fold increase in sensitivity but also reproducible measurements. The porous silica network offers a unique environment for stabilizing SER active metal particles and the high surface area increase the interaction between the analyte and metal particles. The sol-gel has been coated on the inside walls of glass samples vials, such that urine specimens may simply be introduced for analysis. Here we present the surface-enhanced Raman spectra of a series of barbiturates, actual urine specimens, and a drug 'spiked' urine specimen. The utility of pH adjustment to suppress dominant biochemicals associated with urine is also presented.