A new double-sided grating coupled optical sensor using a cross-shaped microchannel for minimizing the dispersion effect

• A new DSGW coupled optical sensor with a cross-shaped microchannel was tested to minimize the dispersion effect.
• The refractive index sensitivity and resolution of sucrose solutions were 26.76 RIU−1 and 6.3 × 10−5 RIU.
• The proposed sensor has well demonstrated the immune binding reaction of anti-DNP antibody recognizing DNP.

Optical biosensors have become a powerful detection and analysis tool for broad applications in pharmaceuticals, environmental monitoring and biomedical research. The present paper reports the design, analysis, manufacture and test of a novel double-sided grating waveguide (DSGW) coupled optical sensor utilizing a cross-shaped microchannel to minimize the dispersion outcome. Numerical and experimental studies were conducted to explore the transport and dispersion phenomena in the microchannel of an optical sensor. In view of the experiments using a sucrose solution as the sample fluid, the detected signals from a DSGW coupler were utilized to appraise the sensor performance in terms of sensitivity and refractive index resolution. The developed optical sensor with the design of cross-shaped microchannel was used to the immunoassay of surface binding reaction of antibodies-dinitrophenol (DNP) recognizing antigens-DNP to display the efficacy of decreasing the unfavorable dispersion effect.