Charge transport through an eight-base pair methylated DNA strand and its native counterpart have been investigated. We focus on three factors, contact coupling, decoherence and temperature, which can contribute to DNA charge transport. Our results show that with the same choice of contact coupling, in the phase-coherent limit the transmission of the methylated strand is smaller in the bandgap at energies close to the highest occupied molecular orbital (HOMO), while inside the HOMO band, the transmission is oscillatory and the methylated DNA may have a larger transmission in certain energy windows. The trend in transmission also holds in the presence of the decoherence though there is a crossover in the transmission of the native and methylated strands away from the HOMO level. We also find that the transport depends on the strength of contact coupling and the measurement temperature.

In this paper we present a multilayer device based on a-Si:H/a-SiC:H that operates as photodetector and optical filter. The use of such device in protein detection applications is pertinent in Fluorescence Resonance Energy Transfer (FRET) measurements that demand the detection of visible fluorescent signals located at specific wavelengths bands. This device was designed to operate in the visible range with a selective sensitivity dependent on the applied electrical bias. Several nanosensors were tested with a commercial spectrophotometer to judge the performance of the FRET signals using glucose solutions of different concentrations. Two nanosensors (FLIPglu-90μM and FLIPglu-600μM) were tested with a commercial spectrofluorimeter to judge the performance of the FRET signals by using glucose solutions of different concentrations. These measurements were carried out by using these nanosensors both in the free form and immobilized form on inner epidermis of onion bulb scale. The proposed device was used to demonstrate the possibility of FRET signals detection, using visible signals of similar wavelength and intensity. The device sensitivity was tuned to enhance the wavelength band of interest using adequate electrical biasing.

The covalent functionalization of photosynthetic proteins with properly tailored organic molecular antennas represents a powerful approach to build a new generation of hybrid systems capable of exploiting solar energy. In this paper the strategy for the synthesis of the tailored aryleneethynylene organic fluorophore (AE) properly designed to act as light harvesting antenna is presented along with its successful bioconjugation to the photosynthetic reaction center RC from the bacterium Rhodobacter sphaeroides .