Citation: Kamrunnahar, Q.M.;
Haider, F.; Aoni, R.A.; Mou, J.R.;
Shifa, S.; Begum, F.; Abdul-Rashid,
H.A.; Ahmed, R. Plasmonic
Micro-Channel Assisted Photonic
Crystal Fiber Based Highly Sensitive
Sensor for Multi-Analyte Detection.
Nanomaterials 2022, 12, 1444. https://
doi.org/10.3390/nano12091444
Academic Editors: Kosei Ueno
and Jacinto Sá
Received: 27 March 2022
Accepted: 19 April 2022
Published: 23 April 2022
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Article
Plasmonic Micro-Channel Assisted Photonic Crystal Fiber
Based Highly Sensitive Sensor for Multi-Analyte Detection
Q. M. Kamrunnahar
1
, Firoz Haider
2
, Rifat Ahmmed Aoni
3,
* , Jannatul Robaiat Mou
1
, Shamsuttiyeba Shifa
4
,
Feroza Begum
5
, Hairul Azhar Abdul-Rashid
2,
* and Rajib Ahmed
6,
*
1
Department of Electronics & Telecommunication Engineering, Rajshahi University of Engineering &
Technology, Rajshahi 6204, Bangladesh; konaete30@gmail.com (Q.M.K.); jannatulruet@gmail.com (J.R.M.)
2
Faculty of Engineering, Multimedia University, Cyberjaya 63100, Selangor, Malaysia; firozknu@gmail.com
3
Integrated Photonics and Applications Centre, School of Engineering, RMIT University,
Melbourne, VIC 3001, Australia
4
Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka 1000, Bangladesh;
shamsuttiyebashifadu.ac.bd@gmail.com
5
Faculty of Integrated Technologies, Universiti Brunei Darussalam, Gadong BE1410, Brunei;
feroza.begum@ubd.edu.bn
6
School of Medicine, Stanford University, Palo Alto, CA 94304, USA
* Correspondence: rifat.ahmmed.aoni@rmit.edu.au (R.A.A.); hairul@mmu.edu.my (H.A.A.-R.);
rajibah@stanford.edu (R.A.)
Abstract:
A dual-channel propagation controlled photonic crystal fiber (PCF)-based plasmonic sensor
was presented to detect multiple analytes simultaneously. Plasmonic micro-channels were placed on
the outer surface of the PCF, which facilitates an easy sensing mechanism. The sensor was numerically
investigated by the finite element method (FEM) with the perfectly matched layer (PML) boundary
conditions. The proposed sensor performances were analyzed based on optimized sensor parameters,
such as confinement loss, resonance coupling, resolution, sensitivity, and figure of merit (FOM). The
proposed sensor showed a maximum wavelength sensitivity (WS) of 25,000 nm/refractive index
unit (RIU) with a maximum sensor resolution (SR) of 4.0
×
10
−6
RIU for channel 2 (Ch-2), and WS
of 3000 nm/RIU with SR of 3.33
×
10
−5
RIU for channel 1 (Ch-1). To the best of our knowledge,
the proposed sensor exhibits the highest WS compared with the previously reported multi-analyte
based PCF surface plasmon resonance (SPR) sensors. The proposed sensor could detect the unknown
analytes within the refractive index (RI) range of 1.32 to 1.39 in the visible to near infrared region
(550 to 1300 nm). In addition, the proposed sensor offers the maximum Figure of Merit (FOM) of 150
and 500 RIU
−1
with the limit of detection (LOD) of 1.11
×
10
−8
RIU
2
/nm and 1.6
×
10
−10
RIU
2
/nm
for Ch-1 and Ch-2, respectively. Due to its highly sensitive nature, the proposed multi-analyte
PCF SPR sensor could be a prominent candidate in the field of biosensing to detect biomolecule
interactions and chemical sensing.
Keywords:
surface plasmon resonance; photonic crystal fiber; optical fiber sensors; multi-analyte
detection
1. Introduction
In the current COVID-19 pandemic, a highly sensitive, fast response, avoiding false
positive responses, and cost-effective biosensor devices are highly desirable [
1
–
4
]. Gen-
erally, a sensor is an analytical device which is used to sense unknown analytes from the
surrounding medium [
5
,
6
]. A PCF-based SPR sensor for multi-analyte detection can be a
promising candidate due to its highly sensitive nature to small changes of target analytes.
Among the various types of sensors (such as electrochemical, piezoelectric, etc.), optical
sensors are the most preferred due to their quick response [
7
,
8
], lightweight nature [
9
],
remote sensing abilities, and maximum signal-to-noise characteristics [
10
,
11
]. There are
several optical sensing techniques, such as micro-ring resonator, resonant mirror, fiber brag
Nanomaterials 2022, 12, 1444. https://doi.org/10.3390/nano12091444 https://www.mdpi.com/journal/nanomaterials
