Author(s): Yu, XC (Yu, Xiao-Chong); Tang, SJ (Tang, Shui-Jing); Liv, WJ (Liv, Wenjing); Xu, YL (Xu, Yinglun); Gong, QH (Gong, Qihuang); Chen, YL (Chen, You-Ling); Xiao, YF (Xiao, Yun-Feng)

Source: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Volume: 119 Issue: 6 Article Number: e2108678119 DOI: 10.1073/pnas.2108678119 Published: FEB 8 2022

Abstract: Label-free sensors are highly desirable for biological analysis and early-stage disease diagnosis. Optical evanescent sensors have shown extraordinary ability in label-free detection, but their potentials have not been fully exploited because of the weak evanescent field tails at the sensing surfaces. Here, we report an ultrasensitive optofluidic biosensor with interface whispering gallery modes in a microbubble cavity. The interface modes feature both the peak of electromagnetic-field intensity at the sensing surface and high-Q factors even in a small-sized cavity, enabling a detection limit as low as 0.3 pg/cm(2). The sample consumption can be pushed down to 10 pL due to the intrinsically integrated microfluidic channel. Furthermore, detection of single DNA with 8 kDa molecular weight is realized by the plasmonic-enhanced interface mode.

Accession Number: WOS:000758485500017

PubMed ID: 35115398

Author Identifiers:

Author Web of Science ResearcherID ORCID Number

Liu, Wenjing B-3816-2019 0000-0002-9441-8859

Xiao, Yun-Feng C-5398-2008 0000-0002-0296-7130

ISSN: 0027-8424

eISSN: 1091-6490

Full Text: https://www.pnas.org/doi/full/10.1073/pnas.2108678119