title: Oil-encapsulated nanodroplet array for bio-molecular detection.
abstract: Detection of low abundance biomolecules is challenging for biosensors that rely on surface chemical reactions. For surface reaction based biosensors, it require to take hours or even days for biomolecules of diffusivities in the order of 10(-10-11) m2/s to reach the surface of the sensors by Brownian motion. In addition, often times the repelling Coulomb interactions between the molecules and the probes further defer the binding process, leading to undesirably long detection time for applications such as point-of-care in vitro diagnosis. In this work, we designed an oil encapsulated nanodroplet array microchip utilizing evaporation for pre-concentration of the targets to greatly shorten the reaction time and enhance the detection sensitivity. The evaporation process of the droplets is facilitated by the superhydrophilic surface and resulting nanodroplets are encapsulated by oil drops to form stable reaction chamber. Using this method, desirable droplet volumes, concentrations of target molecules, and reaction conditions (salt concentrations, reaction temperature, etc.) in favour of fast and sensitive detection are obtained. A linear response over 2 orders of magnitude in target concentration was achieved at 10 fM for protein targets and 100 fM for miRNA mimic oligonucleotides.
authors.affiliation: Institute of Modern Optical Technologies & Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory of Advanced Optical Manufacturing Technologies & MOE Key Laboratory of Modern Optical Technologies, Soochow University, Suzhou, 215006, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Qiao
authors.forename: Tiantian
authors.initials: T
authors.lastname: Zhang
authors.forename: Tony
authors.initials: T
authors.lastname: Yen
authors.forename: Ti-Hsuan
authors.initials: TH
authors.lastname: Ku
authors.forename: Junlan
authors.initials: J
authors.lastname: Song
authors.forename: Ian
authors.initials: I
authors.lastname: Lian
authors.forename: Yu-Hwa
authors.initials: YH
authors.lastname: Lo
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D057927:Hydrophobic and Hydrophilic Interactions; D035683:MicroRNAs / Q000032:analysis*; D046228:Microarray Analysis; D049329:Nanostructures; D009821:Oils; D009841:Oligonucleotides / Q000032:analysis*; D012825:Silicon / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D019809:Streptavidin / Q000032:analysis*; D013499:Surface Properties
chemical_list: D035683:MicroRNAs; D009821:Oils; D009841:Oligonucleotides; D012822:Silicon Dioxide; D004247:DNA; D019809:Streptavidin; D012825:Silicon