Label-Free Method Using a Weighted-Phase Algorithm To Quantitate Nanoscale Interactions between Molecules on DNA Microarrays

• Published in: Analytical chemistry (Washington) 2017-03, Vol.89 (6), p.3501-3507
• Main Authors: Li, Qi, Fu, Rongxin, Zhang, Junqi, Wang, Ruliang, Ye, Jiancheng, Xue, Ning, Lin, Xue, Su, Ya, Gan, Wupeng, Lu, Ying, Huang, Guoliang
• Format: Article
• Language: English
• Subjects: Algorithms; Arrays; Deoxyribonucleic acid; DNA; DNA - chemical synthesis; DNA - chemistry; Fluorescence; Fluorescence Resonance Energy Transfer; Fretting; Interference; Interferometry; Light; Molecules; Nanoparticles - chemistry; Nanostructure; Nanostructured materials; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Solid surfaces; White light
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.6b04596

White light interference is used as a label-free method to detect nanoscale changes on surfaces. However, the signal-to-noise ratio of the white light interference method is very low, thus resulting in inaccurate results. In this paper, we report a corrected label-free method based on hyperspectral interferometry to overcome the shortcoming of the white light interference method. A platform based on hyperspectral interferometry was established, and a DNA hybridization microarray was constructed to quantitate thickness variation of molecules on a solid surface. We used fluorescence resonance energy transfer (FRET) to validate the results of our method. Compared to conventional fluorescence-labeled method like FRET, our method has advantages because it does not require a fluorescent label and has a detection limit of 1.78 nm, a high accuracy, and wide detection range (5–64 bp).