Chemical Functionalization of Exfoliated Graphene

Graphene is turning out to be the material that will effectively kick-start a new era for nanotechnology. The impressive properties of this atom-thick carbon layer are taking shape and form with early reports of successful applications based on it. The turning point for this material will be its low cost mass production. In this report a chemist’s perspective on the production methods for graphene and the subsequent functionalization processes is discussed

Multichromophores Onto Graphene: Supramolecular Non-Covalent Approaches for Efficient Light Harvesting.

The idea of attaching multiple porphyrins to graphene is explored. A charged porphyrin salt is stabilized onto exfoliated graphene by taking advantage of π-π* interactions and a second porphyrin light harvester is anchored through electrostatic interactions with the former. The interactions are capable of allowing electronic communication of the second, electrostatically attached, porphyrin with graphene, effectively quenching its emission. The graphene-porphyrin-porphyrin triad is examined through optical (UV-Vis, steady state and time resolved photoluminescence) techniques, while electrochemistry is employed to study the thermodynamically favored pathways through which the interaction occurs. The porphyrin that is electrostatically stabilized onto the graphene nanoensemble shows lifetimes one order of magnitude faster than its π-π* stacked analogue suggesting a more efficient pathwa

Genetic elimination of field-cage populations of Mediterranean fruit flies

The Mediterranean fruit fly (medfly, Ceratitis capitata Wiedemann) is a pest of over 300 fruits, vegetables and nuts. The sterile insect technique (SIT) is a control measure used to reduce the reproductive potential of populations through the mass release of sterilized male insects that mate with wild females. However, SIT flies can display poor field performance, due to the effects of mass-rearing and of the irradiation process used for sterilization. The development of female-lethal RIDL (release of insects carrying a dominant lethal) strains for medfly can overcome many of the problems of SIT associated with irradiation. Here, we present life-history characterizations for two medfly RIDL strains, OX3864A and OX3647Q. Our results show (i) full functionality of RIDL, (ii) equivalency of RIDL and wild-type strains for life-history characteristics, and (iii) a high level of sexual competitiveness against both wild-type and wild-derived males. We also present the first proof-of-principle experiment on the use of RIDL to eliminate medfly populations. Weekly releases of OX3864A males into stable populations of wild-type medfly caused a successive decline in numbers, leading to eradication. The results show that genetic control can provide an effective alternative to SIT for the control of pest insects

New hybrid materials with porphyrin-ferrocene and porphyrin-pyrene covalently linked to single-walled carbon nanotubes.

Novel porphyrin derivatives bearing additional pyrene or ferrocene units as light harvesting antenna systems were synthesized and fully characterized. Following a covalent functionalization approach for single-walled carbon nanotubes (SWCNTs), stable SWCNT suspensions in common organic solvents 10 were produced. Subsequently, the resulting porphyrin-pyrene and porphyrin-ferrocene dyads were incorporated onto the nanotubes' backbone yielding donor-donor-acceptor hybrids. The resulting hybrid materials were soluble in common organic solvents and were characterized using micro-Raman, ATR-IR, UV-Vis and photoluminescence spectroscopy, transmission electron microscopy, thermogravimetric analysis and εlectrochemistry. Photoluminescence quenching of the porphyrin emission in both hybrid 15 materials was detected thus suggesting the potentiality of these materials in photoelectrochemical cells