A microfluidic chip based on localized surface plasmon resonance for real-time monitoring of antigen-antibody reactions

Localized surface plasmon resonance (LSPR) connecting to noble metal nanoparticles is an important issue for many analytical and biological applications. Therefore, the development of microfluidic LSPR chip that allows studying biomolecular interactions becomes an essential requirement for micro total analysis systems (mu TAS) integration. However, miniaturized process of the conventional surface plasmon resonance system has been faced with some limitations, especially with the usage of Kretschmann configuration in total internal reflection mode. In this study, we have tried to solve this problem by proposing a novel microfluidic LSPR chip operated with a simple collinear optical system. The poly(dimethylsiloxane) (PDMS) based microfluidic chip was fabricated by soft-lithography technique and enables to interrogate specific insulin and anti-insulin antibody reaction in real-time after immobilizing antibody on its surface. Moreover, the sensing ability of microfluidic LSPR chip was also evaluated with various glucose concentrations. The kinetic constant of insulin and anti-insulin antibody was determined and the detection limit of 100ng/mL insulin was archived.