Team:NU Kazakhstan/FP
The carbon dots
We are for environmentally friendly projects. No longer needed grown algae culture might be then utilized to create carbon dots. The carbon quantum dots have applications in bioimaging, drug delivery, and most importantly in optronics, meaning that they can be used as a material for different types of solar cells. Below is how carbon dots are prepared:
The carbon dots are synthesized from algae as follows: 15 mL of algae culture at an OD of 0.6 at 750 nm absorbance is centrifuged for 40 minutes at 4000 rpm. It is then washed with absolute ethanol three times. Algae is then subjected to hydrothermal process at 200 degrees for nine hours followed by centrifugation and passing through a 0.22 um sterile filter. Three different algae samples were used. In the first one, our genetically engineered algae (CW+ electroporated) was used after incubation with Cr6+ (0.2mM) for three days (left sample). In the second sample, a control (CW+ Wild type) was used with the same amount of Chromium (middle sample) and finally, the wild type (CW+) is used without any Chromium (right side).
The addition of Chromium can influence the fluorescence properties of the Quantum Dots through the creation of metal-carbon bonds [1]. Indeed, Quantum Dots made from wild-type algae without Chromium (right side vial) is different from Wild-type with Chromium (middle vial). Moreover, if more Cr(VI) is converted to Cr(III) as in the case of our own strain, then the colour could also be influenced (left vial). The structural and Photochemical properties of these Carbon Quantum Dots are currently under investigation.
Figure 1. The carbon dots under UV light
Figure 2. The carbon dots under regular light
References
1. Liu, R., Huang, H., Li, H., Liu, Y., Zhong, J., Li, Y., ... & Kang, Z. (2013). Metal nanoparticle/carbon quantum dot composite as a photocatalyst for high-efficiency cyclohexane oxidation. ACS Catalysis, 4(1), 328-336.
