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CRISPR-dCas9 powered impedimetric biosensor for label-free detection of circulating tumor DNAs     
Yazarlar
Doç. Dr. Zihni Onur UYGUN Doç. Dr. Zihni Onur UYGUN
Kafkas Üniversitesi, Türkiye
Levent Yeniay
Ege Üniversitesi, Türkiye
Ferhan Girgin Sağın
Ege Üniversitesi, Türkiye
Özet
Label-free biosensors which can be integrated into lab-on-a-chip platforms have the advantage of using small volumes for rapid and inexpensive measurements contrary to label-based technologies which are often more costly and time-consuming. In this study, graphene oxide screen printed electrodes (GPHOXE) were modified by deactivated Cas9 (dCas9) proteins and synthetic guide RNA (sgRNA) as the biorecognition receptor for label-free detection of circulating tumor DNAs (ctDNA). This was achieved by detection of a tumor related mutation (PIK3CA exon 9 mutation) via sequence-specific recognition followed by electrochemical impedance spectroscopy (EIS) analysis. The biosensor showed high specificity as there was no impedance signal for other ctDNA sequences, even the single nucleotide mismatch. dCas9-sgRNA modified biosensor demonstrated linear detection limits between 2 and 20 nM for 120 bp ctDNA's in 40 s. The calibration curve showed good linearity, LOD was calculated as 0.65 nM and LOQ was calculated as 1.92 nM. Selectivity and repeatability studies were carried out in real blood samples and the recovery was higher than 96%. In conclusion, dCas9-sgRNA was effectively immobilized and optimized on GPHOXE as the selective biorecognition receptor of this ultrafast impedimetric biosensor. The CRISPR-dCas9 powered impedimetric system showed good selectivity, high repeatability and good recovery properties. This is the first literature to report the use of CRISPR/Cas technology as a label-free tool that can be used in an impedimetric system for detection of ctDNA's.
Anahtar Kelimeler
Impedimetric biosensor | Circulating tumor DNA | Chronoimpedance | CRISPR/Cas9 technology | Deactivated Cas9 | Label-free analysis | Electrochemical impedance spectroscopy | Liquid biopsy | Cancer diagnosis
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı ANALYTICA CHIMICA ACTA
Dergi ISSN 0003-2670
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q1
Makale Dili İngilizce
Basım Tarihi 07-2020
Cilt No 1121
Sayı 1
Sayfalar 35 / 41
Doi Numarası 10.1016/j.aca.2020.04.009
Makale Linki http://dx.doi.org/10.1016/j.aca.2020.04.009