Abstract
Nanophotonics, and more specifically plasmonics, provides a rich toolbox for biomolecular sensing, since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels. So far, biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes. However, the phase response of the plasmonic resonances have rarely been exploited, mainly because this requires a more sophisticated optical arrangement. Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics. It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration. This unique combination allows the detection of atomically thin (angstrom-level) topographical features over large areas, enabling simultaneous reading of thousands of microarray elements. As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components, the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes. Our research opens new horizons for on-site disease diagnostics and remote health monitoring.
Highlights
Biosensing is one of the most sought-after applications in the field of nanophotonics because the enhanced light–matter interactions via sub-wavelength confinement and amplification of optical near-fields give access to unprecedented real-time, label-free and highly sensitive optical signal transductions[1,2,3,4,5,6,7,8,9,10]
Several attempts have been made to engineer point-of-care (POC) biosensors that leverage nanoplasmonics[27,28,29,30]. Most of these devices rely on amplitude interrogation in which a narrow-band illumination source, such as a light-emitting diode (LED), is tuned to the plasmonic resonance, and the intensity variations due to the spectral resonance shifts that are induced by local refractive index changes are quantified on an imaging sensor, for example, a cellphone camera[31], among other
The variation of the extraordinary transmission (EOT) peak position and its bandwidth should be sufficiently small within a chip and between chips fabricated on wafers in different batches
Summary
Biosensing is one of the most sought-after applications in the field of nanophotonics because the enhanced light–matter interactions via sub-wavelength confinement and amplification of optical near-fields give access to unprecedented real-time, label-free and highly sensitive optical signal transductions[1,2,3,4,5,6,7,8,9,10]. The small-volume, near-field resonant plasmonic modes act as perfect probes to monitor minute local refractive index changes caused by molecular-binding events on the sensor surface. Several attempts have been made to engineer point-of-care (POC) biosensors that leverage nanoplasmonics[27,28,29,30] Most of these devices rely on amplitude (intensity) interrogation in which a narrow-band illumination source, such as a light-emitting diode (LED), is tuned to the plasmonic resonance, and the intensity variations due to the spectral resonance shifts that are induced by local refractive index changes are quantified on an imaging sensor, for example, a cellphone camera[31], among other
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
