Effect of band gap of graphene oxide on interaction with bovine serum albumin: Correlation of band gap with sensitivity

In the direction of developing new and reliable prognostic tools, metamaterial-based biosensor device is an emergent potential field. The special design of metamaterial provides signature frequency features of healthy or diseased tissues. In the current work we have studied the single split resonance device (SSR) using graphene oxide (GO) as probe for the accelerated and selective detection of bovine serum albumin (BSA). Further, we have used different band gap GO to interpret the structure-property relationship. Spectroscopy methods have been employed to further support the SSR results. 1 ppm solution of mGO-0.5 (band gap ∼1.35 eV) shows sequential increase in sensitivity on increasing amount of BSA. Figure-of-merit (FoM) of SSR biosensor also increased from 57 to 82 and highest Q-factor calculated for mGO-1 is ∼47 making it a good candidate as probe molecule. This work lays out a correlation of degree of GO functionalization with a physical parameter, i.e., band gap for activity towards protein molecules. Also, as the SSR devices use large wavelength radiation with high resolution and accuracy for quantitative estimation of analyte, these are potential non-invasive point-of-use portable diagnostic and early disease diagnosis devices.