Pradeep Kumar Maharana

Ultrasensitive Plasmonic Imaging Sensor Based on Graphene and Silicon

We propose an ultrasensitive, accurate, and cost effective surface plasmon resonance sensor based on graphene-on-aluminum and silicon. An angular interrogation method has been theoretically used to study the performance of the sensor in terms of imaging sensitivity, which quantifies the rate of change of slopes of the reflectance curve close to resonance angle. Different optimized design parameters have been reported. It is found that the imaging sensitivity of an aluminum-based sensor is 750% greater than gold, the most widely used SPR active metal. However, graphene-on-aluminum not only prevents the aluminum oxidation but, a monolayer of graphene-on-aluminum exhibits ~400% larger imaging sensitivity compared to that of a conventional gold-film based SPR sensor.

Electric field enhancement in surface plasmon resonance bimetallic configuration based on chalcogenide prism

An aluminium-gold configuration for electric field enhancement based on surface plasmon resonance phenomenon is proposed. Our results and study show that for optimized bimetallic configuration (6 nm Au and 29 nm Al) along with chalcogenide prism, the electric field enhancement at the metal-analyte interface is more than 15 times greater and its probing depth is more than 300% longer than that of the gold based BK7 configuration thereby opening a new window for monitoring the biomolecular interactions in the vicinity of metal-analyte interface for various applications.

On the Field Enhancement and Performance of an Ultra-Stable SPR Biosensor Based on Graphene

The effect of graphene on the electric field enhancement and performance of SPR-based sensor has been proposed and compared with Ag-Au bimetallic configuration. We found that a monolayer of graphene on Ag not only addresses the oxidation problem of Ag, but it also shows field enhancement as compared with the widely reported Ag-Au bimetallic combination. Detailed calculations and simulations show that the proposed graphene-based sensor has higher sensitivity and narrower full-width at half-maximum than bimetallic. In addition, the better biomolecules adhesion due to graphene because of π-stacking interaction may open a new window for ultra-stable high performance biosensors for real time bimolecular interactions.

On the Performance of Highly Sensitive and Accurate Graphene-on-Aluminum and Silicon-Based SPR Biosensor for Visible and Near Infrared

We demonstrate the numerical analysis of surface plasmon resonance biosensor based on graphene on aluminum and silicon. Employing matrix method, it is found that the proposed sensor exhibits high imaging sensitivity ∼400 RIU−1 to 550 RIU−1 in a large dynamic range from visible to near IR region. It is observed that the application of monolayer or bilayer graphene over aluminum not only protects it from oxidation but also enhances the adsorption of biomolecules, which results in the detection of large refractive indices ranging from aqueous solution to biomolecules (refractive index 1.330 to 1.480) with overall high performance in terms of imaging sensitivity and detection accuracy.

Low index dielectric mediated surface plasmon resonance sensor based on graphene for near infrared measurements

We numerically demonstrate and propose a low index dielectric (Teflon) mediated surface plasmon resonance (SPR) sensor based on graphene in a dielectric?metal?dielectric configuration, for near infrared measurements, by taking advantage of the high adsorption efficiency of graphene and the high-resolution resonance feature of low loss surface plasmons. The proposed configuration supports the low loss surface plasmon mode which is evident from its mode field distribution and effective index dispersion. Results show that at a wavelength of 850?nm, the field intensity enhancement factor at the graphene-sensing layer interface for the proposed chalcogenide Ge20Ga5Sb10S65 (2S2G)?Teflon?Au?graphene based sensor is 20% greater than for the 2S2G?Au?graphene based sensor, thereby increasing the imaging sensitivity by 50%. Moreover, for the proposed sensor, the penetration depth of the field into the sensing region is 340% greater than for the conventional (2S2G?Au?graphene) SPR sensor. The proposed SPR sensor could present new possibilities for SPR imaging and detection for highly sensitive and high-throughput assessment of multiple simultaneous molecular interactions.

Low Loss Surface Plasmon Excitation in Graphene Based Dielectric-Metal-Dielectric configuration

We numerically demonstrate the excitation of low loss surface plasmon based on graphene in dielectric-metal-dielectric configuration. The proposed configuration supports low loss surface plasmon mode, evident from mode field distribution and effective index dispersion

Enhancing performance of SPR sensor through electric field intensity enhancement using graphene

An ultra-stable high performance SPR sensor based on graphene on Ag configuration is proposed. The proposed sensor shows enhanced performance as compared to widely reported Au on Ag configuration.