Efficient management of fruit pests by pheromone nanogels

Environment-friendly management of fruit flies involving pheromones is useful in reducing the undesirable pest populations responsible for decreasing the yield and the crop quality. A nanogel has been prepared from a pheromone, methyl eugenol (ME) using a low-molecular mass gelator. This was very stable at open ambient conditions and slowed down the evaporation of pheromone significantly. This enabled its easy handling and transportation without refrigeration, and reduction in the frequency of pheromone recharging in the orchard. Notably the involvement of the nano-gelled pheromone brought about an effective management of Bactrocera dorsalis, a prevalent harmful pest for a number of fruits including guava. Thus a simple, practical and low cost green chemical approach is developed that has a significant potential for crop protection, long lasting residual activity, excellent efficacy and favorable safety profiles. This makes the present invention well-suited for pest management in a variety of crops.

Co-assembled white-light-emitting hydrogel of melamine

A coassembled light-harvesting hydrogel of melamine (M), 6,7-dimethoxy-2,4[1H, 3H]-quinazolinedione (Q) with riboflavin (R), is used to produce a white-light-emitting hydrogel (W-gel) by mixing with the dye rhodamine B (RhB) in a requisite proportion. Addition of R to the Q solution causes both static and dynamic quenching to the emission of Q as evident from the Stern-Volmer plot and the emission of R shows a gradual increase in intensity. On addition of RhB to an aqueous solution of R, fluorescence resonance energy transfer (FRET) occurs, showing an emission peak at 581 nm. In a solution of constant molar ratio of Q and R, addition of RhB causes a quenching of emission of R with no effect on the emission of Q, indicating that the energy transfer takes place only between R and RhB. In the MQR coassembled hydrogel containing RhB, the gel melting temperature is lower than those of MQ and MQR gel, but the storage modulus remains almost unaffected. The oscillatory stress experiment indicates a gradual decrease of critical stress values for breaking of MQ, MQR, and W-gels attributed to the coassembly. In contrast to the solution of Q and R, energy transfer occurs on addition of RhB to the MQ gel. By varying the RhB and R concentration in the 1:1 MQ gel white light emission is observed for the W-gel composition having molar ratio of M:Q:R:RhB = 100:100:0.5:0.02 with the Commission Internationale de L'eclairage (CIE) coordinates of 0.31 and 0.36 for the excitation at 360 nm. However, in the sol state, the CIE coordinates of the hybrid differ significantly from those of the white light.

A peptide based two component white light emitting system

A peptide based two component white light emitting system has been designed and developed on the basis of a co-assembly of a PDI containing peptide system as an acceptor and a stilbene containing peptide system as a donor in organic solvents.