Abstract
An electrochemical aptasensor for detection of trace amounts of aflatoxin M1 was developed. This required immobilization of aptamer on screen printed gold electrode comprising of working electrode, counter electrode and reference electrode and was achieved by sequentially layering dithiodipropionic acid, streptavidin and biotinylated-tetraethylene glycol-aptamer. Immobilization of aptamer was monitored by cyclic voltammetry. Peak current in square wave voltammogram was inversely related to logarithmic concentration of aflatoxin M1. Dynamic range of sensor was 1–105 ppt aflatoxin M1. Sensor can be regenerated by treating electrode with 10% sodium dodecyl sulfate or 40 mM tris-HCl (pH 8.0) containing 10 mM ethylenediaminetetraacetic acid and 0.02% tween-20.
Highlights
Mycotoxins can result in carcinogenic, mutagenic and estrogenic effects and these are hazardous for humans and animals
Measurement of Square wave voltammetry (SWV) under variable concentrations of aflatoxins and during regeneration Aptamer-immobilized electrode was treated with known concentration (1, 10, 102, 103, 104 and 105 ppt) of aflatoxin M1 (AFM1) solubilised in tris buffer (20 mM tris-HCl, pH 7.6 containing 100 mM NaCl, 2 mM MgCl2, 5 mM KCl and 1 mM CaCl2) for 30 min at room temperature
Streptavidin and aptamer were sequentially layered over the electrode surface, these resulted in lowering of peak current
Summary
Mycotoxins can result in carcinogenic, mutagenic and estrogenic effects and these are hazardous for humans and animals. Enzyme-linked immunosorbent assay-based methods are relatively fast and are widely used for screening of samples These methods require specific antibodies which are used as ligand for analytes. Aptamers are single stranded DNA or RNA molecule generally comprising of less than 80 nucleotides and are selected from nucleic acid library ranging from 1013 to 1015 random sequences These are selected through the process referred ‘Systematic Evolution of Ligand by Exponential Enrichment’ (Ellington and Szostak 1990; Tuerk and Gold 1990). Aptamers against AFM1 have been generated (Dinckaya et al 2011; Malhotra et al 2014; Nguyen et al 2013; Sharma et al 2017; Pandey et al 2017) and used for developing aptasensors These sensors have low dynamic range and poor sensitivity. Developed electrochemical aptasensor has dynamic range from 1 to 105 ppt AFM1
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
