Abstract
Hydrothermal synthesis of carbon quantum dots (CQDs) from natural biomass is a green and sustainable route for CQDs applications in various fields. In this work, the preparation and characterization of CQDs based on quinoa saponin were investigated. The optimum synthetic conditions determined by orthogonal experiments were as follows: 2 g quinoa saponin powder and 0.04 mol ethylenediamine reacted at 200°C for 10 h. The relative fluorescence quantum yield (QY = 22.2%) can be obtained, which is higher than some results reported in the literatures. The prepared CQDs had a small and uniform size (∼2.25 nm) and exhibited excitation wavelength-dependent blue light emission behavior. The CQDs displayed excellent sensitivity for Co2+ detection along with good linear correlation ranging from 20 to 150 µM and the detection limit of 0.49 µM. The CQDs prepared in this experiment were successfully implanted into soybean sprouts for fluorescence imaging. The sprouts could grow healthily even soaked in the CQDs solution for two weeks, demonstrating the low toxicity of the CQDs. The advantages of the CQDs, such as low cost, ease of manufacture, nontoxicity, and stability, have potential applications in many areas such as metal ion detection and biosensing.
Highlights
As an important component of vitamin B12, cobalt promotes human bone marrow hematopoiesis and hemoglobin synthesis and increases the number of red blood cells [1]
The Carbon quantum dots (CQDs) were synthesized by a hydrothermal method from quinoa saponin
The FL properties of CQDs were largely influenced by preparation conditions, which need to be further optimized. e FL quantum yield (QY) of CQDs was used as a criterion to find the optimal synthesis conditions
Summary
As an important component of vitamin B12, cobalt promotes human bone marrow hematopoiesis and hemoglobin synthesis and increases the number of red blood cells [1]. There are more methods to determine cobalt ions, such as mass spectrometry [3], atomic absorption [4], and electrochemical methods [5]. These methods can detect trace amounts of cobalt ions, they still have some disadvantages, such as complicated test operations, timeconsuming, and expensive test instruments. E fluorescence detection method has attracted increasing attention due to its simplicity, good sensitivity with selectivity, faster response time, minimal interference effect, and relatively low-cost. CQDs have attracted more and more attention due to their excellent properties, including good fluorescence characteristics, water solubility, bio-compatibility, and low toxicity. Based on the excellent properties, CQDs were widely applied in the fields of detection, drug delivery, and bioimaging [6,7,8,9]. e emergence of CQDs has enriched the application scope of this class of carbon nanomaterials, but the problems of complex postprocessing and low yield still affect their practical applications. erefore, the development of carbon sources with abundant sources, low prices, and high yields has been a matter of great interest
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
