The physics of extreme sensitivity in whispering gallery mode optical biosensors

Lòpez-Yglesias, Xerxes; Gamba, Jason M.; Flagan, Richard C.

doi:10.1063/1.3698319

Cited by 21 publications

(15 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Optimal configurations for spherical WGM sensors were identified, including the resonator size, coupling distance, and operational wavelength, from which single particle sensitivity was predicted. Sensitivity limits in other detection schemes, such as the backscattering geometry, and plasmonically enhanced setups [166,170,171] have also been considered (see below).…”

Section: Theory Of Whispering Gallery Mode Sensingmentioning

confidence: 99%

Whispering gallery mode sensors

2015

View full text Add to dashboard Cite

We present a comprehensive overview of sensor technology exploiting optical whispering gallery mode (WGM) resonances. After a short introduction we begin by detailing the fundamental principles and theory of WGMs in optical microcavities and the transduction mechanisms frequently employed for sensing purposes. Key recent theoretical contributions to the modeling and analysis of WGM systems are highlighted. Subsequently we review the state of the art of WGM sensors by outlining efforts made to date to improve current detection limits. Proposals in this vein are numerous and range, for example, from plasmonic enhancements and active cavities to hybrid optomechanical sensors, which are already working in the shot noise limited regime. In parallel to furthering WGM sensitivity, efforts to improve the time resolution are beginning to emerge. We therefore summarize the techniques being pursued in this vein. Ultimately WGM sensors aim for real-world applications, such as measurements of force and temperature, or alternatively gas and biosensing. Each such application is thus reviewed in turn, and important achievements are discussed. Finally, we adopt a more forward-looking perspective and discuss the outlook of WGM sensors within both a physical and biological context and consider how they may yet push the detection envelope further.

show abstract

Section: Theory Of Whispering Gallery Mode Sensingmentioning

confidence: 99%

Whispering gallery mode sensors

2015

View full text Add to dashboard Cite

show abstract

“…For details of this derivation we refer to [80]. For other resonator geometries such as toroids, this analysis has do be done by simulation [81], because no analytic equations that describe the confined light fields are available. In practice, the sensor response is often experimentally determined (calibrated) for different solution concentration levels [51, 82–84].…”

Section: Optical Resonator-based Biomolecular Sensors: Mechanisms mentioning

confidence: 99%

“…Very high sensitivity allows the detection of single particles such as polystyrene nanospheres and virus particles [3, 32]. Recent developments include efforts to further improve the sensitivity [58, 81, 147, 152, 161], multiplexing capability [49] and functionalization strategies [16, 54]. …”

Section: Optical Resonator Biosensors: Materials and Geometriesmentioning

confidence: 99%

“…The modal volumes of toroidal resonators are smaller than those of microspheres of comparable diameter, and the resonators also have ultrahigh Q factors [186] because of the almost atomically smooth surface produced by reflowing glass. Thus, the toroid geometry boasts a sensitivity comparable to that of the microsphere and is a good candidate for achieving single molecule detection [30, 66, 67, 70, 81]. Toroids could potentially be produced in arrays like those described for disks and rings.…”

Section: Optical Resonator Biosensors: Materials and Geometriesmentioning

confidence: 99%

“…Computational schemes can also be employed to calculate the toroid response to detection events in order to achieve higher sensitivitys [81]. …”

Section: Optical Resonator Biosensors: Materials and Geometriesmentioning

confidence: 99%

See 2 more Smart Citations

Review Label-free detection with high-Q microcavities: a review of biosensing mechanisms for integrated devices

2012

View full text Add to dashboard Cite

Optical microcavities that confine light in high-Q resonance promise all of the capabilities required for a successful next-generation microsystem biodetection technology. Label-free detection down to single molecules as well as operation in aqueous environments can be integrated cost-effectively on microchips, together with other photonic components, as well as electronic ones. We provide a comprehensive review of the sensing mechanisms utilized in this emerging field, their physics, engineering and material science aspects, and their application to nanoparticle analysis and biomolecular detection. We survey the most recent developments such as the use of mode splitting for self-referenced measurements, plasmonic nanoantennas for signal enhancements, the use of optical force for nanoparticle manipulation as well as the design of active devices for ultra-sensitive detection. Furthermore, we provide an outlook on the exciting capabilities of functionalized high-Q microcavities in the life sciences.

show abstract

Ultraspecific and Highly Sensitive Nucleic Acid Detection by Integrating a DNA Catalytic Network with a Label‐Free Microcavity

Zhang

Yin

et al. 2014

Small

View full text Add to dashboard Cite

Nucleic acid detection with label-free biosensors circumvents costly fluorophore functionalization steps associated with conventional assays by utilizing transducers of impressive ultimate detection limits. Despite this technological prowess, molecular recognition at a surface limits the biosensors’ sensitivity, specificity, and reusability. It is therefore imperative to integrate novel molecular approaches with existing label-free transducers to overcome those limitations. Here, we demonstrate this concept by integrating a DNA strand displacement circuit with a micron-scale whispering gallery mode (WGM) microsphere biosensor. The integrated biosensor exhibits at least 25-fold improved nucleic acid sensitivity, and sets a new record for label-free microcavity biosensors by detecting 80 pM (32 fmol) of a 22nt oligomer; this improvement results from the catalytic behavior of the circuit. Furthermore, the integrated sensor exhibits extremely high specificity; single nucleotide variants yield 40- to 100-fold lower signal. Finally, the same physical sensor was demonstrated to alternatingly detect 2 different nucleic acid sequences through 5 cycles of detection, showcasing both its reusability and its versatility.

show abstract

The physics of extreme sensitivity in whispering gallery mode optical biosensors

Cited by 21 publications

References 44 publications

Whispering gallery mode sensors

Whispering gallery mode sensors

Review Label-free detection with high-Q microcavities: a review of biosensing mechanisms for integrated devices

Ultraspecific and Highly Sensitive Nucleic Acid Detection by Integrating a DNA Catalytic Network with a Label‐Free Microcavity

Contact Info

Product

Resources

About