Starch-based Nanomaterials by Cristian Camilo Villa Zabala

Author:Cristian Camilo Villa Zabala
Language: eng
Format: epub
ISBN: 9783030425425
Publisher: Springer International Publishing

In the last decades the development of quantum dots (QDs) has been one of the most important areas in nanotechnology research. (Duan et al. 2015; Li et al. 2015) QDs are semiconductor nanocrystals with sizes ranging from 1 to 10 nm and that have size-selective optical properties due to their quantum confinement effect generating great interest in optoelectronics, biosensing, bioimaging and medicine.(Al-Douri et al. 2018). However, most of the reported QDs are made from toxic materials, limiting their application in some areas. Due to this carbon based quantum dots have emerged as an alternative to traditional QDs. (Al-Douri et al. 2018). As interest in carbon based QDs has increased, so has the search of new materials for their precursors and recent reports have shown that starch can be used as a material in QDs synthesis. Carbon based QDs have been made from starch of different botanical sources, including potato, yam, rice and maize and cassava. (Al-Douri et al. 2018; M. Liu et al. 2016; Qiang et al. 2019; Yan et al. 2015).

In general, starch based QDs are synthetized through decomposition of the starch structure into graphene, either through strong acid hydrolysis assisted with microwave irradiation or ultrasound or hydrothermal methods. Al-Douri et al. (2018) synthetized starch based QDs from different botanical sources using either H2SO4 or H3PO4 as hydrolyzing agent and different micro way irradiation times. Results showed that light emission properties of the QDs can be tuned by changing the hydrolyzing agent and irradiation time, as for example blue light emitting QDs were obtained by using H2SO4 and 4 minutes’ irradiation and increasing irradiation time to 8 minutes the emitted green light. Figure 3.3 shows a schematic representation of the starch based QDs synthesis and while Fig. 3.4 shows their light emitting properties.

Fig. 3.3Schematic representation of the starch based QDs synthesis. Reproduced with permission from Al-Douri et al. (2018)

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