طريقة خضراء مناسبة لتخليق نقاط الكربون المضيئة من الجزر الصالح للأكل وتطبيقاته.

A Convenient Green Method to Synthesize Luminescent Carbon Dots from Edible Carrot and Its Applications

In this study, a simple single-stage procedure depending upon refluxing Iraqi edible carrot with aqueous trisodium phosphate (TSP) has been used to synthesize blue color luminescent carbon dots (CDs). Optimization study indicate that refluxing 5 g of carrot in 100 mM TSP aqueous solution for 120 min is adequate to produce highly luminescent blue CDs. The Fourier-transform infrared (FTIR) spectrum of carrot extract (CE) and carbon dots (CDs) is explained that the -C=O peak observed in 1740 and 1650 cm−1 in the CE was completely lost in CDs, indicate that the carbonyl group was undertook carbonization and form more sp2 hybridized carbon.
Furthermore, the 1H NMR spectra of CE and CDs showed that the number of signals observed between 3 and 4 ppm in the CE was reduced considerably in CDs, indicating that some sugar residues undergone carbonization. These results confirmed that the carbohydrates present in the carrot undergone carbonization to produce luminescent CDs. Scanning Electron Microscopy (SEM) images showed that CDs are almost spherical in shape and the size is around 6.40 – 25.76 nm. Energy dispersive X-ray (EDX) spectrum confirmed the presence of carbon in the samples.
The CDs produced are used as luminophore to image bacteria through fluorescence microscopy. CDs have membrane good permeability and minimum toxicity against Gram-negative and Gram-positive bacteria. The CDs capability for direct reduction of silver ions to elemental silver (Ag0) and gold ions to elemental gold (Au0) without additional reducing and stabilizing agent was demonstrated. The resulting Ag and Au nanoparticles have a size of (20.40 – 59.44 nm) and (14.57 – 38.33 nm), respectively. Significantly higher values of Prothrombin Time (PT) and Activated partial Thromboplastin time (APTT) are found with AgNPs when compared with those without AgNPs, at the probability value of P = 0.05. On the other hands, there is no any significant effect of health status, gender, and smoking activity on the values of PT and APTT.