Aminoguanidine hydrazones (AGHs) are a class of compounds that have interesting pharmacological activities. They are derived from the same chemical group as aminoguanidine, so it has mixed properties (receptor and donor) in the formation of hydrogen bonds. Its anticancer agent properties were recently highlighted, but the molecules of this class have solubility in aqueous solutions that can be considered low. The identification of this class, by a simple, sensitive and low-cost technique, such as electrochemistry, which also allows the evaluation of its solubilization process through agents such as PAMAM dendrimer is the main objective of the work described here. The electrochemical response of the LQM10 (AGH derivative) was evaluated, as well as its behavior in different electrochemical sensors. Electrochemical experiments were performed in buffered (phosphate at pH 7.02 and acetate at 4.5). LQM10 has a reversible oxidation peak with a potential of +0.22 V. It was efficiently detected in different electrodes tested (glass carbon/CNT, glass carbon/CNT/PAMAM), which proves the viability of the electrodes for various analyses and has the determination of the apparent constant association, indicating its interaction with the analysis that is higher in the presence of the PAMAM encapsulating agent. This was corroborated by the results for the modified gold electrode with MUA and PAMAM. The sum of the results shows the possibility of electrochemically evaluating the Aminoguanidine hydrazone derivative, the viability of electrodes employed and the greater so-How to cite this paper:

The Zika virus is a flavivirus spread by the Aedes aegypti mosquito, which also transmits dengue and chikungunya. Current forms of control include elimination of mosquito breeding sites, use of insecticides, repellents and other means. The present study developed new adsorbent materials based on silica and biomaterials capable of releasing an Aedes aegypti mosquito repellent. The materials synthesized were characterized by Fourier-Transform Infrared, thermogravimetric analysis, Scanning Electron Microscopy and Brunauer, Emmett and Teller analysis and tested with citronella, an essential oil widely recognized as a natural insect repellent. The materials presented type IV isotherms, with type H1 hysteresis, characteristic of mesoporous materials, with pore diameters of between 50 Å and 80 Å. Materials based on silica-chitosan-glutaraldehyde dried in an oven (SCGO) and silica-chitosan-glutaraldehyde dried under a vacuum (SCGV) were found to produce more controlled release of citronella essential oil. The bioassay test was performed using a horizontal double-choice olfactometer. The adsorbent SCGO remained stable for the four hours of the bioassay, while the commercial repellent became ineffective after two hours of release. The production of a prototype in the form of bracelets, stickers releasing a volatile repellent is therefore proposed as a method for the control of the mosquito in urban areas.

In this study, we report the effect of the proportion of CdSe/CdS ultrasmall quantum dots (USQDs) conjugated on reduced graphene oxide (rGO). The proposed conjugation used a bond between the hydroxyl groups of the USQDs and the carboxylic groups of the rGO. The formation of the CdSe/CdS-rGO nanocomposites was confirmed by Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), fluorescence (FL), cyclic voltammetry (CV), and photocurrent response versus time (PR). The FTIR results confirmed the bond between the hydroxyl groups present in the CdSe/CdS USQDs with the carboxyl groups of the rGO and with a higher USQD proportion, and the interactions also occur in the epoxide and hydroxyl groups. HRTEM images confirmed the FTIR results. FL spectra of the nanocomposite exhibited a luminescence quenching with USQD proportion. The time-resolved fluorescence observed that the nonradiative decay rate is due to the electron transfer process, reducing lifetime. CV experiments showed that the USQD proportion increases on the rGO-promoted better reversibility of the peak of the Fe 3+ /Fe 2+ system. PR results showed a very weak photocurrent on the rGO when illuminated at 375 nm that increased with the increase of the nanocomposite. Therefore, we have demonstrated that it is possible to tune the optical and electrical properties of the rGO-CdSe/CdS USQD nanocomposites.