b c...Shridhar Manjunath1*, Buddini I. Karawdeniya1, Adam Damry2, Lei Xu1, Khosro Z. Kamali1, Mohsen...

Currently, optical sensors for diabetes and multiple sclerosis are bulky lab-based devices with low sensitivity and requires labelling of biomarkers. As a result, health diagnosis is very expensive, and not readily available. In this work, we employ, dielectric nanoresonators to obtain high sensitivity which are non-invasive, label-free, and can be easily integrated into point-of-care devices. Biosensing with high Q-factor dielectric metasurfaces Shridhar Manjunath 1 *, Buddini I. Karawdeniya 1 , Adam Damry 2 , Lei Xu 1 , Khosro Z. Kamali 1 , Mohsen Rahmani 1 , Colin Jackson 2 , and Dragomir Neshev 1 1 ARC Centre of Excellence TMOS, Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, ACT, Australia 2601; 2 Research School of Chemistry, Australian National University, ACT, Australia 2601; *[email protected] Figure- 1 a) Schematics of a single unit cell of the metasurface. b) Numerically simulated 2D plot of transmission spectra vs refractive index change. c) 1D plot of transmission spectra v Abstract • We immobilised bioreceptors on to our metasurface using silane surface chemistry (As shown in the figure 2a). • The bioreceptor (protein G- Antibody BSA) combination is used to capture small quantities of BSA (analyte of interest). • As demonstrated in figure 2b, we can observe characteristic shifts in the resonance dips. v Results In this work, we demonstrated a proof of concept to detect low levels of biomolecules using metasurfaces. This process can be extended to a comprehensive range of biomarkers (antibodies, antigens, proteins, glycans, etc. ) by using appropriate surface anchors to selectively retain them. v Conclusion • Metasurfaces are an array of subwavelength resonating particles that strongly interacts with the immediate surroundings 1-4 . • The resonance frequency of metasurfaces changes with respect to refractive index (RI) of the surroundings, hence acts as a refractive index sensor 2-4 . • The sensitivity (S) depends on Quality-factor (Q-factor) and losses in the material. Q ≈ "#$%&'&(# )"#*+#&(, "#$%&'&(# -./01 • In this work, we employ high Q-factor dielectric resonators to obtain high sensitivity (see figure 1). • By employing RI sensing method one can detect small quantities of biomolecules around the metasurface. v Introduction Figure- 2 a) Image of the metasurface sample inside the microfluidics chip. b) Schematics of the functionalization process of the metasurface. c) SEM image of the fabricated sample. d) Experimental transmission spectra after attaching each biomolecule. a OV 2 OV 1 r 1 *2 r 2 *2 g Glymo Protein G anti BSA BSA OV 1 -r 1 = 65 nm and r 2 = 130 nm OV 2 -r 1 = 65 nm and r 2 = 160 nm a = 480 nm, g = 60 nm, and height = 70 nm Refractive index Wavelength (nm) 1.35 1.45 1.55 760 840 800 820 780 0 1 0.5 1. S. Manjunath, et al., Adv. Opt. Mater., 2020, 1901658. 2. N. Bontempi, et al., Nanoscale, 2017, 9, 4972. v References 750 760 770 780 790 0.4 0.6 0.8 Transmission Wavelength (nm) 1.33 1.35 a b c a b 3. F. Yesilkoy, et al., Nat. Photonics, 2019, 13, 390-396. 4. O. Yavas, et al., Nano Lett., 2017, 17, 4421-4426. S= 23 245 67 600 620 640 660 680 700 Wavelength (nm) aSi Protein G & anti BSA BSA c d 200 nm

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Transcript of b c...Shridhar Manjunath1*, Buddini I. Karawdeniya1, Adam Damry2, Lei Xu1, Khosro Z. Kamali1, Mohsen...

Biosensing with high Q-factor dielectric metasurfacesShridhar Manjunath1*, Buddini I. Karawdeniya1, Adam Damry2, Lei Xu1, Khosro Z. Kamali1, Mohsen Rahmani1, Colin Jackson2,

and Dragomir Neshev1

1ARC Centre of Excellence TMOS, Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, ACT, Australia 2601; 2Research School of Chemistry, Australian National University, ACT, Australia 2601;

*[email protected]

Figure- 1 a) Schematics of a single unit cell of the metasurface. b) Numericallysimulated 2D plot of transmission spectra vs refractive index change. c) 1Dplot of transmission spectra

v Abstract

• We immobilised bioreceptors on to our metasurface using silane

surface chemistry (As shown in the figure 2a).

• The bioreceptor (protein G- Antibody BSA) combination is used to

capture small quantities of BSA (analyte of interest).

• As demonstrated in figure 2b, we can observe characteristic shifts

in the resonance dips.

v Results

In this work, we demonstrated a proof of concept to detect low levels of biomolecules using metasurfaces. This process can be extended to a comprehensive range of biomarkers (antibodies, antigens, proteins, glycans, etc. ) by using appropriate surface anchors to selectively retain

them.

v Conclusion

• Metasurfaces are an array of subwavelength resonating particles

that strongly interacts with the immediate surroundings1-4.

• The resonance frequency of metasurfaces changes with respect to

refractive index (RI) of the surroundings, hence acts as a refractive

index sensor2-4.

• The sensitivity (S) depends on Quality-factor (Q-factor) and losses

in the material. Q≈ "#$%&'&(# )"#*+#&(,"#$%&'&(# -./01

• In this work, we employ high Q-factor dielectric resonators to

obtain high sensitivity (see figure 1).

• By employing RI sensing method one can detect small quantities

of biomolecules around the metasurface.

v Introduction

Figure- 2 a) Image of the metasurface sample inside the microfluidics chip.b) Schematics of the functionalization process of the metasurface. c) SEMimage of the fabricated sample. d) Experimental transmission spectra afterattaching each biomolecule.

OV2OV1

r1*2

r2 *2

Glymo Protein G anti BSA BSA

OV1 - r1 = 65 nm and r2 = 130 nm OV2 - r1 = 65 nm and r2 = 160 nma = 480 nm, g = 60 nm, and height = 70 nm

Refractive index

Wav

elen

gth

(nm

)

1.35 1.45 1.55760