A high sensitivity and low-cost polycarbonate (PC)-based biosensor

This study integrates the techniques of nano electroforming, hot embossing, and electrochemical deposition to develop a disposable, low cost, and high sensitivity nanostructure biosensor. A modified anodic aluminum oxide (AAO) barrier-layer surface is used as the template for nickel thin film deposition. After etching the AAO template off, a 3D mold of the concave nano structure array is created. The fabricated 3D nickel mold is further used for replica molding of a nano-structure polycarbonate (PC) substrate by hot embossing. An Au thin film is than sputtered on the PC substrate to form the electrode followed by the deposition of an orderly and uniform gold nanoparticle (GNP) layer on the 3D Au electrode using electrochemical deposition. Finally, silver nanoparticles (SNP) are deposited on the uniformly deposited GNPs to enhance the conductivity of the sensor. Electrochemical impedance spectroscopy (EIS) analysis is then used to detect the concentration of the target element. The sensitivity of the proposed scheme on the detection of the dust mite antigen Der p2 can reach 0.1pg/ml.