TY - JOUR
T1 - How Fast It Can Stick
T2 - Visualizing Flow Delivery to Microtoroid Biosensors
AU - Suebka, Sartanee
AU - Nguyen, Phuong Diem
AU - Gin, Adley
AU - Su, Judith
N1 - Funding Information:
We acknowledge partial financial support from the NIH R03AG055020, R21MH111109, NSF 1842045, Gordon & Betty Moore Foundation (grant GBMF7555.14), Flinn Foundation (grant 26223) Arizona Alzheimer’s Consortium, and the University of Arizona Cancer Center. Sartanee Suebka was supported by the Royal Thai Government Scholarship from the Ministry of Higher Education, Science, Research and Innovation, Thailand.
Publisher Copyright:
© 2021 American Chemical Society
PY - 2021/7/23
Y1 - 2021/7/23
N2 - Sensitive and rapid biosensors are of critical importance for a variety of applications including infectious disease detection and monitoring as well as medical diagnostics and drug discovery. Whispering gallery mode microtoroid optical resonators are among the most sensitive biochemical sensors in existence. When combined with frequency-locking and data-processing techniques, these sensors have been shown to be capable of single-molecule detection in under 30 s. The sensitivity of these sensors is affected by how a concentration of analyte molecules is transported to the surface of the sensors and the average time it takes the molecules to bind at that concentration. Currently, one question in the field is that at these low concentrations, how these microsensors achieve such rapid response times. Here, we reconcile theory and experiment and demonstrate through flow visualization experiments and finite-element simulations that the total analyte arrival and binding time can be on the order of seconds. This fast response time provides an advantage over nanoscale sensors such as nanowires or nanorods. We anticipate that these results can help us to control, with confidence, when and how many molecules bind to these sensors, thus enabling the building of faster and more sensitive sensors.
AB - Sensitive and rapid biosensors are of critical importance for a variety of applications including infectious disease detection and monitoring as well as medical diagnostics and drug discovery. Whispering gallery mode microtoroid optical resonators are among the most sensitive biochemical sensors in existence. When combined with frequency-locking and data-processing techniques, these sensors have been shown to be capable of single-molecule detection in under 30 s. The sensitivity of these sensors is affected by how a concentration of analyte molecules is transported to the surface of the sensors and the average time it takes the molecules to bind at that concentration. Currently, one question in the field is that at these low concentrations, how these microsensors achieve such rapid response times. Here, we reconcile theory and experiment and demonstrate through flow visualization experiments and finite-element simulations that the total analyte arrival and binding time can be on the order of seconds. This fast response time provides an advantage over nanoscale sensors such as nanowires or nanorods. We anticipate that these results can help us to control, with confidence, when and how many molecules bind to these sensors, thus enabling the building of faster and more sensitive sensors.
KW - advection
KW - analyte transport time
KW - diffusion
KW - flow visualization
KW - microtoroid optical resonator
KW - whispering gallery mode
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U2 - 10.1021/acssensors.1c00748
DO - 10.1021/acssensors.1c00748
M3 - Article
C2 - 34078073
AN - SCOPUS:85108560863
VL - 6
SP - 2700
EP - 2708
JO - ACS Sensors
JF - ACS Sensors
SN - 2379-3694
IS - 7
ER -