Synthesis of Heart/Dumbbell-Like CuO Functional Nanostructures for the Development of Uric Acid Biosensor

Smartphone integrated handheld Long Range Surface Plasmon Resonance based fiber-optic biosensor with tunable SiO2 sensing matrix

In the present work, a novel smartphone assisted fiber optic (FO)-Long range surface plasmon resonance (LRSPR) based biosensor is proposed. In the developed biosensor, the inbuilt color sensitive property of the digital camera present in the smartphone is used for the monitoring of blue and red color channel intensities. This will replace the most exploited diffraction gratings or narrow band filters used for analyzing the spectral data in reported smartphone based SPR sensors. The proposed technique helps in improving the sensitivity and reduces the chances of wrong detection. For the first time, SiO₂ nanostructured film is employed as the dielectric sensing layer to excite the Long range surface plasmons (LRSPs) in the dielectric-metal-dielectric configuration. The proposed FO-LRSPR biosensor possess limit of detection of 0.02 mM and sensitivity of 0.9/mM and, for uric acid detection in the 0.1 mM-1 mM concentration range. The novel fabricated sensor which is found to be stable up to 24 weeks can be effectively utilized in health sector and environment monitoring and it possess the ability of point-of-care detection, even in rural and remote areas.

Refractive index tuning of SiO2 for Long Range Surface Plasmon Resonance based biosensor

A novel, highly sensitive and low cost Long Range Surface Plasmon Resonance (LRSPR) biosensor for detecting uric acid, as a model analyte, has been developed in this work. Silicon dioxide (SiO₂) having low and tunable refractive index has been chosen as the dielectric layer for the excitation of LRSP modes replacing the most explored Cytop and Teflon polymers. The prepared LRSPR based uric acid bio-sensor gives good response characteristics with a high sensitivity of about 21.6°/mM and low limit of detection (LOD) of 0.02 mM. The fabricated LRSPR sensor was also evaluated to detect uric acid in real serum samples. The results yield a great scope to promote the development of robust, efficient and highly selective LRSPR based biosensors with SiO₂ as tunable dielectric layer.