Background: Biosensor detects the binding event of biologically relevant molecules, which are analyte
and ligand. Showing improved sensitivity is the key and primary characteristic of a high-performance biosensor,
which displays lower abundance of an analyte. Here, we preferred the silicon substrate on impedance
sensor to demonstrate the improvement in the sensitivity with different band-gaps.
Methods: we have fabricated two band-gaps on the sensing substrate with the sizes of micrometer and
nanometer. These gaps were measured to be 85.5 ± 5 µm and 125 ± 3 nm, respectively. Squamous cell carcinoma
(SCC) antibody and antigen interaction for the cancer detection was demonstrated on these gaps.
Results: It was found that nano-gap is having higher sensitivity than micro-gap. Further, gold nanoparticle conjugated
SCC antigen was found to show the improvement with the micro-gap.
Conclusion: This research has evidenced that lesser band-gap (nano) exhibits a good sensitivity for the detection
of SCC antigen rather than micro-gap. Gold nanoparticle conjugation with antigen is suitable for microgaps,
whereas no significant improvement with nano-gaps was observed.