(A) study on the synthesis of nanostructured materials and fabrication of microfluidics devices for biosensor application

Abstract

Microfluidic devices and nano materials play key roles in the emerging biosensor applications such as lab-on-a-chip, which include pretreatment and purification of protein sample, and diagnosis and therapy of disease. Recently, microfluidic devices for biological sample pretreatment have become important in the design of analytical devices for high-throughput applications such as functional validation of proteins and peptides in large-scale proteome characterizations. In addition, nano materials for diagnosis and therapy are young and rapid emerging field such as point-of-care (POC) biosensor, tumor pretargeting agent, drug delivery vehicle and diagnostic imaging agent. In this study, microvalves based on ionic polymer metal composite (IPMC) were developed for microfluidic application, and multi-functional polydiacetylene-modified reduced graphene oxide (PDA/RGO) were prepared for the nano materials for biosensor applications. First, simple and highly efficient microvalve systems based on IPMC diaphragm actuator has been developed. Our microvalve system operates when ‘open’ and ‘close’ voltage are applied. Displacement of IPMC in the microvalve was measured by laser displacement meter. By applying open and close voltages, the operation of the valve becomes faster. Fluorescence images of the flow in the fabricated IPMC microvalve system showed a successful operation of flow control in the microfluidic channel. Second, graphene nano sheet hybridized with polydiacetylene (PDA) was explored as the electrochemical biosensor applications. Self-assembly and photo-polymerization chemistry of diacetylenic monomers on reduced graphene oxide (RGO) for noncovalent functionalization was used for high solubility and further functionality of graphene in water. This enabled regular graphene micropatterns on large substrates with chemical bonding and biological interactions. PDA/RGO nano hybrid demonstrates the formation of conjugated polymer on graphene for fluorescence and el...