Ultrasensitive electrochemical genosensor for detection of CaMV35S gene with FeO-Au@Ag nanoprobe.

Yongkang Ye, Shen Mao, Shudong He, Xuan Xu, Xiaodong Cao, Zhaojun Wei, Sundaram Gunasekaran

Journal: Talanta 2020;206():120205

PMID: 31514877

Full Text on Elsevier Science View on PubMed

Abstract

We report an attomolar sensitive electrochemical genosensor for the detection of cauliflower mosaic virus 35S (CaMV35S) gene. The sandwich-type genosensor uses gold-silver core-shell (Au@Ag)-loaded iron oxide (FeO) nanocomposite (FeO-Au@Ag) as label of signal DNA probe (sDNA). Electrochemical sensing is accomplished at interface of electrodeposited AuNPs and carboxylated multiwalled carbon nanotubes-modified glassy carbon electrode through the specific interaction between the capture probe and target CaMV35S (tDNA), and tDNA and the labeled sDNA. The detection sensitivity was improved by the amplified reduction signal of hydrogen peroxide (HO), which takes advantage of the enhanced electrocatalytic activity of FeO-Au@Ag. Under the optimal experimental conditions, an ultralow limit of detection was calculated to be 1.26 × 10 M (S/N = 3), and the blank value subtracted reduction signal of HO of the sensor increased linearly with the logarithm of CaMV35S concentration over a wide range (1 × 10 M to 1 × 10 M). This genosensor displayed excellent stability, selectivity and reproducibility, and was successful in detecting the target CaMV35S in genetically modified tomato samples.

Address: School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.; School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, China.; School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China. Electronic address: [email protected].; Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA. Electronic address: [email protected].

DOI: 10.1016/j.talanta.2019.120205

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MeSH Terms: Biosensing Techniques, Caulimovirus, DNA Probes, DNA, Viral, Electrochemical Techniques, Electrodes, Gold, Hydrogen Peroxide, Solanum lycopersicum, Magnetite Nanoparticles, Nanocomposites, Nanotubes, Carbon, Nucleic Acid Hybridization, Oxidation-Reduction, Plants, Genetically Modified, Silver