One-step fabrication of three-dimensional macropore copolymer-modified polycarbonate array by photo-crosslinking for protein immunoassay.

A photocross-linked copolymer was prepared, and could rapidly form a macropore structure in phosphate buffer solution (PBS) without the addition of porogen. The photo-crosslinking process contained the crosslinking of the copolymer itself and that with the polycarbonate substrate. The three-dimensional (3D) surface was achieved through one-step photo-crosslinking of the macropore structure. The macropore structure can be finely regulated by multiple dimensions, including monomer structure of the copolymer, PBS and copolymer concentration. Compared with the two-dimensional (2D) surface, the 3D surface has a controllable structure, a high loading capacity (59 μg cm) and immobilization efficiency (92%), and the effect of inhibiting the coffee ring for protein immobilization. Immunoassay results show that a 3D surface immobilized by IgG has high sensitivity (LOD value of 5 ng mL) and broader dynamic range (0.005-50 μg mL). This simple and structure-controllable method for preparing 3D surfaces modified by macropore polymer has great potential applications in the fields of biochips and biosensing.