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Updated: Mar 3, 2026
A Label-free Technique for the Spatio-temporal Imaging of Single Cell Secretions
Published on: November 23, 2015
Molecular overlap with optical near-fields based on plasmonic nanolithography for ultrasensitive label-free detection
Kiheung Kim1, Wonju Lee1, Kyungwha Chung2
1School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea.
Abstract:
In this work, we investigate the detection sensitivity of surface plasmon resonance (SPR) biosensors by engineering spatial distribution of electromagnetic near-fields for colocalization with molecular distribution. The light-matter colocalization was based on plasmonic nanolithography, the concept of which was confirmed by detecting streptavidin biotin interactions on triangular nanoaperture arrays after the structure of the aperture arrays was optimized for colocalization efficiency. The colocalization was shown to amplify optical signature significantly and thereby to achieve detection on the order of 100 streptavidin molecules with a binding capacity below 1fg/mm2, an enhancement by more than three orders of magnitude over conventional SPR detection.
