Biomolecular recognition by label free interferometric methods

Markku Känsäkoski, Sanna Uusitalo, Meng Wang, Risto Myllylä, Leena Hakalahti

Research output: Contribution to conferenceConference articleScientific

Abstract

Ageing population in Europe will increasingly burden the health care system, e.g. chronic diseases are becoming more and more common and are influencing the quality of life of rapidly increasing number of people. New solutions for biomolecular recognition measurements are required to reduce the number of costly laboratory tests, hospital controls and idle visits to general practices. Optical interferometric measurement methods are extremely sensitive and thus they are very suitable for biomolecular recognition. Usual sensitivity range for interferometric methods is from 10-5 to 10-8 refractive index units. This large dynamic range covers well most biomolecular applications. In an integrated Young interferometer sensor, which we have focused on in our studies, the incident sensing light is divided into two parallel light paths, reference and sample path. Sample path has an antibody coating on its surface, where the measured analyte (antigen) binds specifically and the other light path acts as a reference of the measurement to compensate, e.g., temperature fluctuations. This compensation explains the extremely good sensitivity obtained with most Young interferometers. It also makes the sensor more cost efficient since there is no need for very precise stabilisation of humidity and temperature around the sensor chip. In this paper we present the theoretical and empirical functioning and sensitivity of two integrated Young interferometers. We have studied the sensitivity of a channel waveguide based interferometer with integrated Y-junction as a beam splitter and a vertically integrated dual-slab waveguide interferometer. The sensitivity of the channel waveguide based Young interferometer was found to be in the order of 10-8 effective refractive index units (i.e., in the order of 10-6 refractive index units). Compared to this conventional channel waveguide based Young’s interferometer; we found that the dual-slab waveguide interferometer (Farfield Inc.) has the advantages of easy fabrication and large tolerance to the input coupling beam. The sensor performance was estimated by using glucose solutions with various concentrations. Glucose concentrations within physiological range 30mg/dl ~ 500mg/dl are of the most interest. As a result the dual-slab waveguide interferometer yields an average phase resolution of 0.002 rad which corresponds to an effective refractive index change of 4×10-8 (tai to a refractive index change of 5×10-6).
Original languageEnglish
Publication statusPublished - 2007
MoE publication typeNot Eligible
EventInternational Symposium Bio meets Nano and IT - Halle, Germany
Duration: 4 Dec 20074 Dec 2007

Conference

ConferenceInternational Symposium Bio meets Nano and IT
CountryGermany
CityHalle
Period4/12/074/12/07

Fingerprint

interferometers
waveguides
refractivity
sensitivity
slabs
sensors
glucose
antigens
beam splitters
antibodies
optical measurement
health
dynamic range
humidity
stabilization
chips
costs
coatings
fabrication
temperature

Keywords

  • Biomolecular recognition
  • biosensor
  • interferometry

Cite this

Känsäkoski, M., Uusitalo, S., Wang, M., Myllylä, R., & Hakalahti, L. (2007). Biomolecular recognition by label free interferometric methods. Paper presented at International Symposium Bio meets Nano and IT, Halle, Germany.
Känsäkoski, Markku ; Uusitalo, Sanna ; Wang, Meng ; Myllylä, Risto ; Hakalahti, Leena. / Biomolecular recognition by label free interferometric methods. Paper presented at International Symposium Bio meets Nano and IT, Halle, Germany.
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keywords = "Biomolecular recognition, biosensor, interferometry",
author = "Markku K{\"a}ns{\"a}koski and Sanna Uusitalo and Meng Wang and Risto Myllyl{\"a} and Leena Hakalahti",
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Känsäkoski, M, Uusitalo, S, Wang, M, Myllylä, R & Hakalahti, L 2007, 'Biomolecular recognition by label free interferometric methods' Paper presented at International Symposium Bio meets Nano and IT, Halle, Germany, 4/12/07 - 4/12/07, .

Biomolecular recognition by label free interferometric methods. / Känsäkoski, Markku; Uusitalo, Sanna; Wang, Meng; Myllylä, Risto; Hakalahti, Leena.

2007. Paper presented at International Symposium Bio meets Nano and IT, Halle, Germany.

Research output: Contribution to conferenceConference articleScientific

TY - CONF

T1 - Biomolecular recognition by label free interferometric methods

AU - Känsäkoski, Markku

AU - Uusitalo, Sanna

AU - Wang, Meng

AU - Myllylä, Risto

AU - Hakalahti, Leena

N1 - Project code: 9446

PY - 2007

Y1 - 2007

N2 - Ageing population in Europe will increasingly burden the health care system, e.g. chronic diseases are becoming more and more common and are influencing the quality of life of rapidly increasing number of people. New solutions for biomolecular recognition measurements are required to reduce the number of costly laboratory tests, hospital controls and idle visits to general practices. Optical interferometric measurement methods are extremely sensitive and thus they are very suitable for biomolecular recognition. Usual sensitivity range for interferometric methods is from 10-5 to 10-8 refractive index units. This large dynamic range covers well most biomolecular applications. In an integrated Young interferometer sensor, which we have focused on in our studies, the incident sensing light is divided into two parallel light paths, reference and sample path. Sample path has an antibody coating on its surface, where the measured analyte (antigen) binds specifically and the other light path acts as a reference of the measurement to compensate, e.g., temperature fluctuations. This compensation explains the extremely good sensitivity obtained with most Young interferometers. It also makes the sensor more cost efficient since there is no need for very precise stabilisation of humidity and temperature around the sensor chip. In this paper we present the theoretical and empirical functioning and sensitivity of two integrated Young interferometers. We have studied the sensitivity of a channel waveguide based interferometer with integrated Y-junction as a beam splitter and a vertically integrated dual-slab waveguide interferometer. The sensitivity of the channel waveguide based Young interferometer was found to be in the order of 10-8 effective refractive index units (i.e., in the order of 10-6 refractive index units). Compared to this conventional channel waveguide based Young’s interferometer; we found that the dual-slab waveguide interferometer (Farfield Inc.) has the advantages of easy fabrication and large tolerance to the input coupling beam. The sensor performance was estimated by using glucose solutions with various concentrations. Glucose concentrations within physiological range 30mg/dl ~ 500mg/dl are of the most interest. As a result the dual-slab waveguide interferometer yields an average phase resolution of 0.002 rad which corresponds to an effective refractive index change of 4×10-8 (tai to a refractive index change of 5×10-6).

AB - Ageing population in Europe will increasingly burden the health care system, e.g. chronic diseases are becoming more and more common and are influencing the quality of life of rapidly increasing number of people. New solutions for biomolecular recognition measurements are required to reduce the number of costly laboratory tests, hospital controls and idle visits to general practices. Optical interferometric measurement methods are extremely sensitive and thus they are very suitable for biomolecular recognition. Usual sensitivity range for interferometric methods is from 10-5 to 10-8 refractive index units. This large dynamic range covers well most biomolecular applications. In an integrated Young interferometer sensor, which we have focused on in our studies, the incident sensing light is divided into two parallel light paths, reference and sample path. Sample path has an antibody coating on its surface, where the measured analyte (antigen) binds specifically and the other light path acts as a reference of the measurement to compensate, e.g., temperature fluctuations. This compensation explains the extremely good sensitivity obtained with most Young interferometers. It also makes the sensor more cost efficient since there is no need for very precise stabilisation of humidity and temperature around the sensor chip. In this paper we present the theoretical and empirical functioning and sensitivity of two integrated Young interferometers. We have studied the sensitivity of a channel waveguide based interferometer with integrated Y-junction as a beam splitter and a vertically integrated dual-slab waveguide interferometer. The sensitivity of the channel waveguide based Young interferometer was found to be in the order of 10-8 effective refractive index units (i.e., in the order of 10-6 refractive index units). Compared to this conventional channel waveguide based Young’s interferometer; we found that the dual-slab waveguide interferometer (Farfield Inc.) has the advantages of easy fabrication and large tolerance to the input coupling beam. The sensor performance was estimated by using glucose solutions with various concentrations. Glucose concentrations within physiological range 30mg/dl ~ 500mg/dl are of the most interest. As a result the dual-slab waveguide interferometer yields an average phase resolution of 0.002 rad which corresponds to an effective refractive index change of 4×10-8 (tai to a refractive index change of 5×10-6).

KW - Biomolecular recognition

KW - biosensor

KW - interferometry

M3 - Conference article

ER -

Känsäkoski M, Uusitalo S, Wang M, Myllylä R, Hakalahti L. Biomolecular recognition by label free interferometric methods. 2007. Paper presented at International Symposium Bio meets Nano and IT, Halle, Germany.