Chemical modification of silicon nitride microsieves for capture of MCF-7 circulating tumor cells of breast cancer

Thien Dien To, Huyen Thoai Le, Mai Ngoc Thi Dinh, Anh Tuan Nguyen, Tin Chanh Duc Doan and Chien Mau Dang

Abstract

Chemical modification of silicon nitride (SiN) microsieves with glutaraldehyde and 3-glycidoxypropyldimethylethoxysilane (GOPS) for bio-coupling with an antibody to capture MCF-7 circulating tumor cells of breast cancer is reported. In this research, the antibody monoclonal anti-cytokerantin–FITC with fluorescein isothiocyanate label was used due to its good selectivity to MCF-7 circulating tumor cells of breast cancer. Modification efficiency was determined by the variation of contact angle. The increase in contact angle of the microsieves treated with glutaraldehyde and GOPS indicated that the microsieve surface changed from hydrophilic to hydrophobic. These results confirmed the successful immobilization of glutaraldehyde and GOPS onto SiN microsieves. Antibody binding effect was evaluated by fluorescence microscopy. Fluorescent images exhibited that GOPS was more effective than the glutaraldehyde treatment. The GOPS-treated microsieves were then used for capture of MCF-7 cells in phosphate buffered saline (PBS). The fluorescent images proved that the surface modification of SiN microsieves with GOPS helped to increase the efficiency of MCF-7 capture