title: Digital DNA detection based on a compact optofluidic laser with ultra-low sample consumption.
abstract: DNA lasers self-amplify optical signals from a DNA analyte as well as thermodynamic differences between sequences, allowing quasi-digital DNA detection. However, these systems have drawbacks, such as relatively large sample consumption and complicated dye labelling. Moreover, although the lasing signal can detect the target DNA, it is superimposed on an unintended fluorescence background, which persists for non-target DNA samples as well. From an optical point of view, it is thus not truly digital detection and requires spectral analysis to identify the target. In this work, we propose and demonstrate an optofluidic laser that has a single layer of DNA molecules as the gain material. A target DNA produces intensive laser emission comparable to existing DNA lasers, while any unnecessary fluorescence background is successfully suppressed. As a result, the target DNA can be detected with a single laser pulse, in a truly digital manner. Since the DNA molecules cover only a single layer on the surface of the laser microcavity, the DNA sample consumption is a few orders of magnitude lower than that of existing DNA lasers. Furthermore, the DNA molecules are stained by simply immersing the microcavity in the intercalating dye solution, and thus the proposed DNA laser is free of any complex dye-labelling process prior to analysis.
authors.affiliation: Graduate School of Nanoscience and Technology and KINC, KAIST, Daejeon, 305-701, Republic of Korea. nandk@kaist.ac.kr.
authors.forename: Wonsuk
authors.initials: W
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, University of Michigan, 1101 Beal Ave., Ann Arbor, MI 48109, USA. xsfan@umich.edu.
authors.forename: Qiushu
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, University of Michigan, 1101 Beal Ave., Ann Arbor, MI 48109, USA. xsfan@umich.edu.
authors.forename: Xudong
authors.initials: X
authors.lastname: Fan
authors.affiliation: Graduate School of Nanoscience and Technology and KINC, KAIST, Daejeon, 305-701, Republic of Korea. nandk@kaist.ac.kr.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Yoon
mesh_terms: D004247:DNA / Q000032:analysis*; D007834:Lasers; D057230:Limit of Detection; D055096:Optical Devices
chemical_list: D004247:DNA