Target-responsive ratiometric fluorescent aptasensor for OTA based on energy transfer between [Ru(bpy) 3 ] 2+ and silica
- PDF / 517,195 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 78 Downloads / 218 Views
ORIGINAL PAPER
Target-responsive ratiometric fluorescent aptasensor for OTA based on energy transfer between [Ru(bpy)3]2+ and silica quantum dots Xi Zhu 1,2 & Wenjing Li 1,2 & Liping Lin 1 & Xiaojuan Huang 1 & Huifeng Xu 3,4 & Guidi Yang 1,2 & Zhenyu Lin 5 Received: 3 September 2019 / Accepted: 30 March 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract A ratiometric fluorescent aptasensor based on energy transfer between [Ru(bpy)3]2+ and silica quantum dots (silica QDs) for assaying OTA was fabricated. The aptamer for OTA was used as the gate to shield the fluorescent reagent [Ru(bpy)3]2+ into mesoporous silica nanoparticle (MSN). In the presence of OTA, the constrained [Ru(bpy)3]2+ was released from MSN due to a target-induced aptamer conformational change. The released [Ru(bpy)3]2+ adsorbed onto the negatively charged silica QDs through electrostatic interaction. This creates appearance of fluorescence from [Ru(bpy)3]2+ at 625 nm and decrease of the fluorescence from silica QDs at 442 nm owing to the energy transfer. The value of FL625nm/FL442nm was in proportion to the concentration of OTA in the range 0.5~100 ng mL−1 with a LOD of 0.08 ng mL−1. Practical applicability of this method was validated by the determination of OTA in flour samples. Keywords Ochratoxin A . Silica quantum dots . Ratiometric fluorescent sensor . [Ru(bpy)3]2+ . Aptamer
Introduction Ochratoxin A (OTA) is a secondary metabolite secreted from fungi species such as Aspergillus and Penicillium during their growth. OTA is chemically stable with very slow degradation rate in the body. Terribly, OTA is known to be nephrotoxic, hepatotoxic, neurotoxic, immunotoxic, and teratogenic to human beings and animals [1], and considered to be a possible carcinogen by the International Agency for Research on Cancer (IARC). Since OTA widely exists in various contaminated crops
and beverages including coffee, wine, grape juice, and dried fruits [2, 3], the European Commission has set the maximum level of OTA at various foodstuffs, such as 5 μg kg−1 for raw cereal grain and 10 μg kg−1 for soluble coffee. Generally, high-performance liquid chromatography (HPLC) [4] is a conventional method for OTA. The researchers have also made great efforts for the determination of OTA, including colorimetric [5–8], fluorescence [9–14], and electrochemistry [15–22]. Among them, the fluorescent method has attracted particular attention due to their high sensitivity and technical simplicity. Various
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-020-04245-3) contains supplementary material, which is available to authorized users. * Huifeng Xu [email protected] * Guidi Yang [email protected] 1
2
Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University, Fuzhou 35002, Fujian,
Data Loading...
