Format

Send to

Choose Destination
Biosens Bioelectron. 2019 Feb 1;126:36-43. doi: 10.1016/j.bios.2018.10.008. Epub 2018 Oct 19.

Vertical flow-based paper immunosensor for rapid electrochemical and colorimetric detection of influenza virus using a different pore size sample pad.

Author information

1
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
2
School of Materials Science and Engineering, UNIST, Ulsan 44919, Republic of Korea.
3
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea; School of Mechanical, Aerospace and Nuclear Engineering, UNIST, Ulsan 44919, Republic of Korea. Electronic address: jjang@unist.ac.kr.

Abstract

We present a novel vertical flow-based paper immunosensor for the rapid and sensitive electrochemical and colorimetric detection of influenza H1N1 viruses using a different pore size (DP) sample pad. The DP sample pad consisted of two different pore size papers: larger pores (diameter: 11 µm) facing the inlet, and smaller pores (diameter: 0.45 µm) facing the conjugate pad. This sample pad offered moderate and uniform flows, and hence concentrated horseradish peroxidase tagged antibodies (HRP-Abs)-H1N1 complexes from 40 µL of sample volumes on a conjugate pad for 2 min after sample injection, thereby providing fast detection (6 min for both detection methods) with 100 µL of flushing afterwards, high sensitivity, and the simplicity of the sensor. The filtration characteristics of the DP sample pad were evaluated using fluorescent beads, indicating that only small-sized bio-particles such as viruses can pass through the sample pad. Sandwich immunoreactions of HRP-Ab-H1N1-Ab were performed on the gold paper electrode of the immunoStrip, which was determined by electrochemical impedance spectroscopy (EIS) measurements. Simultaneously, the color signal of free HRP-Ab captured on the colorimetric zone was obtained using a scanner, and the intensity was analyzed using ImageJ. This immunosensor detected H1N1 virus concentration as low as 3.3 plaque forming units (PFU)/mL (phosphate buffer saline; PBS) and 4.7 PFU/mL (saliva) by EIS, and 1.34 PFU/mL (PBS) and 2.27 PFU/mL (saliva) by the colorimetric method. Furthermore, integrating these two detection methods can reduce false results with double assurance, and this device can provide a simple and economical on-site detection platform.

KEYWORDS:

Colorimetric sensor; Electrochemical sensor; H1N1 influenza virus; Paper sensors; Sandwich immunoreaction; Vertical flow assay

PMID:
30388552
DOI:
10.1016/j.bios.2018.10.008
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center