Desenvolvimento de um novo ponto quântico de carbono a partir de bioprecursores regionais para atuação como sensor de ph e ser uma alternativa aos métodos existentes

Abstract

The promising interest in academic research involving quantum carbon dots (QCDs) is due to the diverse possibilities of applications of these nanoparticles in areas such as physics, biology and chemistry. These applications range from their use as biological sensors and sensors, proton sensors, drug transporters, LEDs production, supercapacitors to indication of the presence of metals in food matrices. All this diversity of use is possible thanks to the more fundamental and particular characteristic of QCDs: its strong ultraviolet absorption capacity extending to the visible, coupled with the fact that its emission of fluorescence is adjustable according to its size and the structural composition of the its surface. This identity gives this nanomaterial excellent characteristics for its use in luminescent analytical determinations based on its optical properties. For this project, the QCDs were prepared using a simple, inexpensive and single-stage approach from regional bioprecursors such as citrus juices, being submitted to hydrothermal treatment at low temperature in a muffle furnace. Subsequent steps of passivation or surface modification were not employed. The QCDs were characterized by absorbance and fluorescence measurements, with etalonamine being the functionalizing agent that presented the highest fluorescence emission when compared to the other agents used. The hydrothermal treatment in the muffle furnace was chosen because it presented a simple, reproducible and friendly synthesis approach. The fluorescence of these QCDs can be significantly suppressed in the presence of must be a basical middle of work. Based on this phenomenon, the results indicated that the relative fluorescence of these PQCs was effectively extinguished and linearly proportional to the increase in pH of the medium and the increase in temperature.