Читать книгу Nanobiotechnology in Diagnosis, Drug Delivery and Treatment - Группа авторов - Страница 62

QDs are fluorescent nanocrystals produced from semiconductor materials with unique optical and electrical properties (Matea et al. 2017). QDs have drawn a lot of attention for their simplicity of synthesis and abundance of the raw material in nature. They are rich in carboxyl groups on their surface, therefore QDs can absorb a lot of single‐strand carcinoembryonic antigen (CEA) aptamer through π‐π stacking interactions, leading to effective fluorescence quenching (Zhu and Gao 2019). The utility of fluorescent properties of QDs for cancer targeting and imaging applications has been suggested in many studies (Laroui et al. 2013; Gao et al. 2014). Semiconductor nanoparticles can accumulate at a target site due to their enhanced permeability and retention at a tumor site. For example, fluorescent QDs conjugated to various peptides specifically target either the vasculature of normal tissues or, alternatively, cancer cells (Fortina et al. 2007). QDs were found to be useful in diagnosis of leishmaniasis, a parasitic disease caused by parasites of the Leishmania type (Andreadou et al. 2016). Authors developed a Leishmania‐specific surface antigen and DNA detection methods based on a combination of magnetic beads and CdSe QDs with a test specificity of 100% and a low limit of detection of 3125 ng μl⁻¹ for Leishmania DNA and 10³ cells ml^–1 for Leishmania protein. Based on obtained results the authors concluded that this method showed considerable potential for clinical application in human and veterinary medicine.