Open AccessSingle-molecule optofluidic microsensor with interface whispering gallery modes
Author(s) -
Xiaonan Yu,
ShuiJing Tang,
Wenjing Liu,
Yinglun Xu,
Qihuang Gong,
You-Ling Chen,
YunFeng Xiao
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2108678119
Subject(s) - whispering gallery wave , biomolecule , resonator , interface (matter) , analyte , microfluidics , optofluidics , materials science , optoelectronics , detection limit , plasmon , evanescent wave , nanotechnology , sensitivity (control systems) , molecule , biosensor , chemistry , electronic engineering , chromatography , gibbs isotherm , organic chemistry , engineering
Significance Optical microresonators have emerged as promising platforms for label-free detection of molecules. However, approaching optimum sensitivity is hindered due to the weak tail of evanescent fields. Here, we report the implementation of the interface modes for ultrasensitive sensing in a microbubble resonator. With the electromagnetic field peaked at the interface between the optical resonator and the analyte solution, interface modes enable sensing of biomolecules with a detection limit of 0.3 pg/cm2 . Single-molecule detection is further demonstrated using the plasmonic-enhanced interface modes. In addition, intrinsically integrated into a microfluidic channel, the sensor exhibits ultrasmall sample consumption down to 10 pL, providing an automatic platform for biomedical analysis.