Seesawed fluorescence nano-aptasensor based on highly vertical ZnO nanorods and three-dimensional quantitative fluorescence imaging for enhanced detection accuracy of ATP

• Published in: Biosensors & bioelectronics 2017-04, Vol.90, p.450-458
• Main Authors: Shrivastava, Sajal, Triet, Nguyen Minh, Son, Young-Min, Lee, Won-Il, Lee, Nae-Eung
• Format: Article
• Language: English
• Subjects: 3D quantitative imaging; Adenosine Triphosphate - chemistry; Adenosine Triphosphate - isolation & purification; Aptamers, Nucleotide - chemistry; Aptasensors; Biomolecules; Biosensing Techniques; Biosensors; Chromium; Fluorescence; Fluorescent Dyes; Imaging; Imaging, Three-Dimensional; Label-free; Limit of Detection; Nanorods; Nanostructure; Nanotubes - chemistry; Quantitative detection; Seesawed fluorescence; Signal-To-Noise Ratio; Spectrometry, Fluorescence; Zinc oxide; Zinc Oxide - chemistry
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.09.089

Probe-mediated fluorescence biosensing methods based on spectrophotometry still have limitations such as detection inaccuracy caused by the occurrence of false signals and lack of simultaneous qualitative and quantitative read-outs with an ultra-low detection limit. Herein, we describe a novel seesawed fluorescence detection strategy based on dual-colour imaging-based quantitation in which the green fluorescence of the capture aptamer decreases and the red fluorescence of the detection aptamer increases simultaneously upon their respective interactions with the target biomolecule. This approach enhances detection accuracy through facilitating identification of probable false-positives in biological samples. Furthermore, combining the seesawed detection scheme with three-dimensional imaging of fluorescence signal enhanced by highly vertical ZnO nanorods increases signal-to-noise ratio, which addresses the limited performance of digital cameras and, in turn, enhances sensitivity and dynamic range. This simple, robust, scalable, imaging-based and label-free fluorescence method allows highly specific and sensitive quantification of biomolecules with excellent reliability. Seesawed fluorescence detection based on dual-colour 3D imaging. Seesawed fluorescence detection of biomolecules was achieved through dual-colour imaging-based quantitation, where green fluorescence of capture aptamers intercalated with SYBR green-I (SGI) decreased and red fluorescence of detection aptamers with an extended DNA sequence required for the formation of DNA-templated silver nanoclusters increased simultaneously after their interaction with target biomolecules. 3D imaging-based quantitation of the two fluorescence signals using vertically aligned ZnO NRs was implemented to precisely monitor changes in ATP levels of cells. The proposed approach will facilitate the development of bioassays and diagnostics with greater precision and ultra-high sensitivity. [Display omitted] •A unique seesawed aptasensor is proposed for highly enhanced detection accuracy.•3D quantitative fluorescence imaging is integrated in biosensor with ZnO nanorods.•A label-free dual-color method developed to eliminate false positives from diagnostics.•Merging qualitative and quantitative biosensing with an ultra-low detection limit.•Highly aligned ZnO NRs on AlGaN-templated sapphire substrate to develop quantitative fluorescence aptasensor.