Development of electrochemical DNA biosensor for DG74 primer usingmodern FFT voltammetryDevelopment of electrochemical DNA biosensor for DG74 primer usingmodern FFT voltammetryDevelopment of electrochemical DNA biosensor for DG74 primer usingmodern FFT voltammetry

سال انتشار: 1395
نوع سند: مقاله کنفرانسی
زبان: انگلیسی
مشاهده: 347

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شناسه ملی سند علمی:

ELECTROCHEMISTRY012_029

تاریخ نمایه سازی: 5 آذر 1397

چکیده مقاله:

DG74 primer is a universal bacterial primer to amplify and detect DNAs from phylogeneticallydivergent bacteria by targeting conserved regions of the 16S rRNA gene [1, 2]. In this study, asimple and rapid fast Fourier transform square-wave voltammetry (FFT-SWV) method fordevelopment of an electrochemical DNA biosensor for DG74 primer , using a gold electrode astransducer and methylene blue (MB) as electroactive label is described. The sensor relies oncovalent attachment of the 19-mer thiolated DNA probe on the gold electrode. Covalently selfassembledprobe could selectively hybridize with a complementary sequence (DG74 primer) insolution to form double-stranded DNA on the surface [3]. The hybridization between the probe andits complementary sequence as the target was studied by modern FFT-SWV signal of MBaccumulated on the modified electrode by scanning the electrode potential between 0.1 and -0.5 V.In this approach the extent of hybridization is evaluated on the basis of the difference between FFTSWVsignals of MB accumulated on the probe modified Au electrode before and afterhybridization. Some hybridization experiments with noncomplementary oligonucleotides werecarried out to assess whether the suggested DNA sensor responds selectively to the target.Furthermore, signal-to-noise ratio was significantly increased by application of discrete fast Fouriertransform (FFT) method [4]. Some experimental variables affecting the performance of thebiosensor including: MB accumulation time, probe SAM formation time and concentration ofprobe and method and required time for hybridazition were investigated. Furthermore effects ofsquare-wave frequency, step potential and pulse amplitude were examined for the optimization ofinstrumental conditions. Diagnostic performance of the biosensor is described and the calibrationgraph is linear between 0.1 and 3 nM. The detection limit was found to be 33 pM and the relativestandard deviation over five independently probe-modified electrodes measured at 1 nM Target,was 1.7%, indicating a remarkable reproducibility of the detection method.

نویسندگان

Hedieh Haji-Hashemi

Center of Excellence in Electrochemistry, faculty of Chemistry, University of Tehran, Tehran, Iran

Parviz Norouzi

Center of Excellence in Electrochemistry, faculty of Chemistry, University of Tehran, Tehran, Iran

Mohammad Reza Ganjali

Center of Excellence in Electrochemistry, faculty of Chemistry, University of Tehran, Tehran, Iran

Farnoush Faridbod

Center of Excellence in Electrochemistry, faculty of Chemistry, University of Tehran