A single-layer, planar, optofluidic Mach–Zehnder interferometer for label-free detection

Because of unique electrical and structural properties, graphene has attracted widespread attention in biosensing applications. In this paper, a single layer of graphene was grown by chemical vapor deposition (CVD). Using graphene as the electric channel, a graphene field effect transistor (G-FET) biosensor was fabricated and used to detect adenosine triphosphate (ATP) and adenosine. Compared with traditional methods, the G-FET biosensor has the advantages of higher sensitivity and better stability. The sensor showed high performance and achieved a detection limit down to 0.5 pM for both ATP and adenosine. Moreover, the G-FET biosensor showed an excellent linear electrical response to ATP concentrations in a broad range from 0.5 pM to 50 μM. The developed graphene biosensor has high sensitivity, simple operation, and fast analysis speed, which may provide a new feasible direction to detect ATP and adenosine. Healthy sexually mature male laboratory Wistar rats, weighing 180-200 gr (“FSUE “Nursery of laboratory animals “Rappolovo”) and having been placed under quarantine not less than for 14 days, were selected for the experiment.

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Label-free real-time optical monitoring of DNA hybridization using SiN Mach–Zehnder interferometer-based integrated biosensing platform

Journal of Biomedical Optics ◽

10.1117/1.jbo.23.12.127002 ◽

2018 ◽

Vol 23 (12) ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

Mohammed Sharif Murib ◽

Daan Martens ◽

Peter Bienstman

Keyword(s):

Real Time ◽

Dna Hybridization ◽

Zehnder Interferometer ◽

Optical Monitoring ◽

Label Free ◽

Mach Zehnder Interferometer

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All-Optical Tunable Plasmonic Biosensor Made of Graphene and Metamaterial

10.21203/rs.3.rs-692445/v1 ◽

2021 ◽

Author(s):

Fariba Lotfi ◽

Nafiseh Sang-Nourpour ◽

Reza Kheradmand

Keyword(s):

Environmental Control ◽

Silicon Layer ◽

Zehnder Interferometer ◽

Label Free ◽

Biomedical Sensing ◽

Highly Sensitive ◽

Lossy Media ◽

Path Structure ◽

Cancerous Cells ◽

Mach Zehnder Interferometer

Abstract We demonstrate a novel, label-free and real-time tunable infrared biosensor by employing surface-plasmon polaritons in asymmetric Mach-Zehnder interferometer. The waveguides cladding in the Mach-Zehnder interferometer is made of lossy media with positive and negative electromagnetic susceptibilities, including metamaterial, metal and graphene. The core consists of dielectric media. We introduce two configurations for our biosensor structure. First configuration is an open-path structure and the second one consists of a sample housing made of a silicon layer around the structure. We also present a tunable biosensor by applying a gate voltage to the graphene in the structure. We employ three different cancerous cells, including cervical, breast and basal, as samples to examine the capabilities of the biosensor. Our biosensor structure is highly sensitive, compared to the existing biosensors in the literature, with the sensitivity for basal cancer cell of 1034THz/RIU. The proposed biosensor structure is compact and easy to fabricate with applications in biomedical sensing and environmental control to detect water pollutants.

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Comparative Study of Microcantilever-Based Sensor for Biosensing Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1064.205 ◽

2014 ◽

Vol 1064 ◽

pp. 205-212

Author(s):

Saurav Verma ◽

Vinod Jain

Keyword(s):

High Precision ◽

Single Layer ◽

Frequency Change ◽

Label Free ◽

Mass Detection ◽

Concentrated Force ◽

Label Free Detection ◽

Micromechanical Sensors ◽

Detection Of Biomolecules ◽

Deformation Stress

Cantilever-based sensors have emerged as a promising label free detection technique, which have been used for high precision mass detection and biomolecular recognition. By surface functionalization, the cantilever can be modified specific to certain compounds detection. Molecules adsorbed to one side of the cantilever will deflect the cantilever due to changes in surface stress. Alternatively, minute mass changes can be detected by monitoring the resonant frequency change of the cantilever for high-precision mass detections. This work is dedicated to finite element (FE) 3Dstructural modeling of three layers micromechanical sensors in ANSYS 13.0 gives 3D model which are close to reality mathematical models. Material used in cantilever for different layers are silicon-dioxide, poly-silicon and nitride. The emphasis of the analysis is put on tile effects of the angle of inclination of the concentrated force upon the deformed shape, the load-deflection relationship stresses and strain for further analysis with a greater degree of accuracy. The model we made is three different model i.e. single layer microcantilevers, three layers microcantilever with same height and three layers with different height. In three layer the centre layer i.e. second layer, is piezoresistive layer that helps to calculate Characteristics i.e. deflection, deformation, stress and strain in the cantilever for the given applied force that can we used for future analysis for the detection of biomolecules in various biosensing application. Finally the comparison of all the three different model of cantilever according to their characteristics.

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