Author : Jiehao Guan
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)
Book Synopsis Development of an Electrochemical Aptasensing Platform Based on Nanomaterials and DNA Nanostructures for Antibiotics Detection in Dairy Products by : Jiehao Guan
Download or read book Development of an Electrochemical Aptasensing Platform Based on Nanomaterials and DNA Nanostructures for Antibiotics Detection in Dairy Products written by Jiehao Guan and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bovine mastitis is the most common disease in dairy cattle, which causes a major economic burden for the dairy industry. Antibiotics have been introduced as veterinary medicine for the prevention and treatment of bovine mastitis for decades. However, the abuse of antibiotics develops the resistance to foodborne pathogens and causes public health issues. Therefore, routine tests to monitor the levels of antibiotics in animal products are in great demand to alleviate food safety concerns. In this dissertation, we proposed a highly sensitive and selective electrochemical aptasensing platform based on nanomaterial fabrication and DNA nanotechnology and a universal aptamer screening procedure for small molecule-specific aptamers selection. The electrochemical performance of the sensor was significantly enhanced by modifying the electrode surface with reduced graphene oxide and gold nanoparticles. We developed a self-assembled tetrahedral DNA nanostructure to precisely control the orientation of immobilized aptamers and their nanospacing from neighboring aptamers to fully realize the target binding affinity. The electrical response of this aptasensor was amplified by almost 100 times and the sensitivity was remarkably improved because of the superior detecting environment. An ultrasensitive label-free electrochemical aptasensor was fabricated to achieve ampicillin qualification and quantification in a wide range of concentrations from 10 pM to 1000 nM with a limit of detection (LOD) of 1 pM in less than 30 min in both buffer systems and real milk samples. An immobilization-free aptamer screening procedure based on graphene oxide (GO) adsorption (GO-SELEX) was designed to select functional ssDNA structures for penicillin G identification. The dissociation constant (Kd) of the selected aptamer was determined as 105.15 ± 1.94 nM using the electrochemical method based on Langmuir binding isotherm. Electrochemical responses to penicillin G concentrations from 0.2 nM to 1000 nM were used to determine a very low LOD of 50 pM. Additionally, the aptasensor was proved capable of detecting penicillin G in spiked milk samples with recovery rates from 98 % to 109%. The specificity of the aptamer sequence was confirmed by a selectivity test against other antibiotics. The reproducibility and stability of the designed aptasensor were also exanimated to verify its potential for on-site analysis.