A nanostructured-nickel based interdigitated capacitive transducer for biosensor applications

This paper presents, for the first time, the development of a nickel-based, reliable alternative electrode for biosensor applications. The electrodes are formed of nanosized nickel patterned as interdigitated structure to form a capacitive biosensor platform. To test the sensing performance of new biosensing platform, we investigated cardiovascular risk marker (C-reactive protein – CRP) and to check the specificity of the bioassay bovine serum albumin (BSA) and prostate specific antigen (PSA) were employed as controls. The nickel-electrode surface was covalently functionalized and characterized by Fourier transform infrared spectroscopy (FT-IR). The detection and quantification of CRP-antigen was performed by impediometric measurements. A detection model for the new biosensing platform was developed using the spectral impediometric responses and are matched with the specific antibody–antigen interaction-model, using the Cole–Cole model parameters. The results and analysis shown that the nanosized, nickel-based-electrode surface could be a good potential to be a cost effective alternative to the conventional gold electrodes with a comparable sensing performance, as shown for CRP, with a detection limit of 1–250 ng/ml. Furthermore, nano-sized nickel-based capacitive electrodes were fabricated using integrated circuit (IC) fabrication processes, providing compatibility for the integration of electronic circuits for single-chip and lab-on-chip biosensing applications.