Robust single-stranded DNA (ssDNA) microarrays are created by attaching amine-modified oligonucleotides to a monolayer of poly-L-glutamic acid (pGlu) that is electrostatically adsorbed onto a chemically modified gold thin film. This surface attachment chemistry methodology is first characterized with a combination of polarization-modulation Fourier transform infrared (PM-FTIR) spectroscopy and surface plasmon resonance (SPR) angle shift measurements. SPR imaging (SPRI) measurements of these ssDNA microarrays are then used to study two surface bioaffinity interactions: (i) the quantitative hybridization adsorption of complementary ssDNA onto mixed ssDNA microarray elements, and (ii) the adsorption of single-stranded binding protein (SSB) onto fully and partially hybridized DNA microarray elements. The Langmuir adsorption coefficient (KAds) of SSB binding to ssDNA was determined to be 5.5 (±0.4)× 109 M-1.

We demonstrate a new strategy for improved stabilization of polydiacetylene micelles. They show temperature-induced color changes, which are fully reversible even at varying pH. A novel azo chromophore-functionalized amphiphilic diacetylene molecule is synthesized and used to prepare self-assembled cylindrical micelles. The micelles can be polymerized by 254 nm light irradiation. The azo chromophores form H- and J-like aggregates in the polydiacetylene micelles and increase the stability of the micelles, which leads to fully reversible thermochromism of the micelles in the temperature range between 20 and 90 °C and the pH range between 5.6 and 9.6.

In this study, the general suitability of quantum dot (QD)-DNA conjugates for the surface plasmon enhanced fluorescence spectroscopy technique is demonstrated. Furthermore, the QD-DNA system is transferred to the platform of surface plasmon enhanced fluorescence microscopy. Using this technique together with a microarray format, in which the sensor-bound single-stranded catcher probes are organized in individual surface spots, results in a simultaneous qualitative analysis of QD-conjugated analyte DNA strands as multicolor images. A clear decomposition of different QD(x)()-DNA(y)() mixtures can be achieved for sequential, as well as mixture injections. Besides this, the study describes the successful approach of measuring spectrally resolved surface plasmon enhanced fluorescence signals derived from catcher probe hybridized QD-DNA conjugates.

Template-induced hydroxyapatite (HA) has broad prospects in the applied fields of regenerative medicine and bone repair. HA thin coatings have been deposited on vertically aligned multiwalled carbon nanotubes (CNTs) via the high-temperature radio-frequency (rf) magnetron sputtering deposition technique. Simulated body fluid (SBF) solution has been used to soak and incubate the HA/CNTs nanocomposites at 37 degrees C. SEM, EDS, XRD, and FTIR characterizations revealed bonelike apatite formation on top of HA/CNTs composites. Coating HA material on well-aligned CNT-template provides a way of combining the superior mechanical properties and chemical stability of the CNTs with the excellent biochemical properties of HA.