title: Approaches to label-free flexible DNA biosensors using low-temperature solution-processed InZnO thin-film transistors.
abstract: Low-temperature solution-processed In-Zn-O (IZO) thin-film transistors (TFTs) exhibiting a favorable microenvironment for electron transfer by adsorbed artificial deoxyribonucleic acid (DNA) have extraordinary potential for emerging flexible biosensor applications. Superb sensing ability to differentiate even 0.5 μL of 50 nM DNA target solution was achieved through using IZO TFTs fabricated at 280 °C. Our IZO TFT had a turn-on voltage (V(on)) of -0.8 V, on/off ratio of 6.94 × 10(5), and on-current (I(on)) value of 2.32 × 10(-6)A in pristine condition. A dry-wet method was applied to immobilize two dimensional double crossover tile based DNA nanostructures on the IZO surface, after which we observed a negative shift of the transfer curve accompanied by a significant increase in the Ion and degradation of the Von and on/off ratio. As the concentration of DNA target solution increased, variances in these parameters became increasingly apparent. The sensing mechanism based on the current evolution was attributed to the oxidation of DNA, in which the guanine nucleobase plays a key role. The sensing behavior obtained from flexible biosensors on a polymeric substrate fabricated under the identical conditions was exactly analogous. These results compare favorably with the conventional field-effect transistor based DNA sensors by demonstrating remarkable sensitivity and feasibility of flexible devices that arose from a different sensing mechanism and a low-temperature process, respectively.
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Joohye
authors.initials: J
authors.lastname: Jung
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Si Joon
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea; Department of Physics and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea.
authors.forename: Keun Woo
authors.initials: KW
authors.lastname: Lee
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Doo Hyun
authors.initials: DH
authors.lastname: Yoon
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Yeong-Gyu
authors.initials: YG
authors.lastname: Kim
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kwak
authors.affiliation: Department of Physics and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea.
authors.forename: Sreekantha Reddy
authors.initials: SR
authors.lastname: Dugasani
authors.affiliation: Department of Physics and SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea. Electronic address: sunghapark@skku.edu.
authors.forename: Sung Ha
authors.initials: SH
authors.lastname: Park
authors.affiliation: School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea. Electronic address: hjk3@yonsei.ac.kr.
authors.forename: Hyun Jae
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000235:genetics*; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007204:Indium / Q000737:chemistry; D008567:Membranes, Artificial; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D013194:Staining and Labeling; D013696:Temperature; D014173:Transistors, Electronic; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D008567:Membranes, Artificial; D007204:Indium; C047711:indium oxide; D004247:DNA; D015034:Zinc Oxide
keywords: DNA; Flexible biosensors; In–Zn–O; Oxide TFTs; Solution-process