Fluorophore-encapsulated nanobeads for on-site, rapid, and sensitive lateral flow assay

https://doi.org/10.1016/j.snb.2023.133364Get rights and content
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Highlights

  • Rapid and accurate early diagnosis is needed for the prevention of epidemics.

  • Conventional lateral flow assay based on gold nanoparticles showed low sensitivity.

  • Fluorophore with large Stokes shift is encapsulated into polystyrene nanobead.

  • Fluorescence enhanced nanobead probe enables higher sensitivity of lateral flow assay.

Abstract

Since December 2019, the rapid and sensitive detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a priority for public health. Although the lateral flow assay (LFA) sensor has emerged as a rapid and on-site SARS-CoV-2 detection technique, the conventional approach of using gold nanoparticles for the signaling probe had limitations in increasing the sensitivity of the sensor. Herein, our newly suggested methodology to improve the performance of the LFA system could amplify the sensor signal with a facile fabrication method by concentrating fluorescent organic molecules. A large Stokes shift fluorophore (single benzene) was encapsulated into polystyrene nanobeads to enhance the fluorescence intensity of the probe for LFA sensor, which was detected on the test line with a longpass filter under ultraviolet light irradiation. This approach provides comparatively high sensitivity with the limit of detection of 1 ng mL−1 for the SARS-CoV-2 spike protein and a fast detection process, which takes less than 20 min. Furthermore, our sensor showed higher performance than gold nanoparticle-based commercial rapid diagnostics test kits in clinical tests, proving that this approach is more suitable and reliable for the sensitive and rapid detection of viruses, bacteria, and other hazardous materials.

Abbreviations

SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2
LFA
Lateral flow assay
PCR
Polymerase chain reaction
RDT
Rapid diagnostic test
AuNP
Gold nanoparticle
SB
Single Benzene
PS
Polystyrene
Ag
Antigen
Ab
Antibody
LOD
Limit of detection
TL
Test line
CL
Control line
CT
Threshold cycle

Data Availability

Data will be made available on request.

Cited by (0)

Sung Eun Seo is a Ph.D. student at the department of civil & environment engineering, Yonsei University. Her research interests include development of monitoring system for environmental hazardous materials based on FET sensor and PCR.

Eunsu Ryu is a M.S. student at the department of chemical and biomolecular engineering, Korea Advanced Institute of Science and Technology (KAIST). Her research interests include development of POCT system based on molecular diagnosis.

Jinyeong Kim earned a Master of Science in chemistry at Chung-Ang University. She is currently a researcher at Korea Research Institute of Bioscience & Biotechnology (KRIBB). Her research interests include synthesis of chemical materials for disease diagnosis and treatment.

Chan Jae Shin is a M.S. student at the department of biotechnology, University of Science and Technology (UST). His research interests include development of 2D material biosensors.

Oh Seok Kwon obtained a Ph.D. in Seoul National University. He is currently a senior researcher in the infectious disease research center at Korea Research Institute of Bioscience & Biotechnology (KRIBB). His research field includes development of electrical biosensors, interfacing chemistry, next-generation polymerase chain reaction.

1

The authors contributed equally to this work.