μ-TAS for label-free biosensing with double-sided grating waveguide

In this study, we demonstrated the feasibility of a μ-TAS (micro total analysis system) for label-free biosensing with double-sided grating waveguide by measuring the refractive index of sucrose solution and immunoassay interaction. The μ-TAS consisted of a durable double-sided grating waveguide biochip and a reusable integrated microfluidic module. The grating chip and the waveguide were fabricated respectively by injection molding and sputtering technology, and therefore, featured the characteristics of low cost and high stability. In addition, the unique coupling characteristics of laser light into the double-sided grating waveguide structure reduced the need of high-precision alignment optical components. Moreover, the integrated microfluidic module was reusable and could be combined with the durable waveguide biochip to form a portable μ-TAS for biosening. Using the μ-TAS presented in this study, the refractive index resolution of sucrose solution and limitation of detection for DNP/anti-DNP interaction were measured to be 4.73×10^-6 RIU and 2.67×10^-7g/ml, respectively.