  The reliability of analysis is becoming increasingly important as
point-of-care diagnostics are transitioning from single analyte detection
towards multiplexed multianalyte detection. Multianalyte detection benefits
greatly from complementary metal-oxide semiconductor (CMOS) integrated sensing
solutions, offering miniaturized multiplexed sensing arrays with integrated
readout electronics and extremely large sensor counts. The development of CMOS
back end of line integration compatible graphene field-effect transistor (GFET)
based biosensing has been rapid during the last few years, both in terms of the
fabrication scale-up and functionalization towards biorecognition from real
sample matrices. The next steps in industrialization relate to improving
reliability and require increased statistics. Regarding functionalization
towards truly quantitative sensors and on-chip bioassays with improved
statistics require sensor arrays with reduced variability in functionalization.
Such multiplexed bioassays, whether based on graphene or on other sensitive
nanomaterials, are among the most promising technologies for label-free
electrical biosensing. As an important step towards that, we report wafer-scale
fabrication of CMOS integrated GFET arrays with high yield and uniformity,
designed especially for biosensing applications. We demonstrate the operation
of the sensing platform array with 512 GFETs in simultaneous detection for
sodium chloride concentration series. This platform offers a truly statistical
approach on GFET based biosensing and further to quantitative and multi-analyte
sensing. The reported techniques can also be applied to other fields relying on
functionalized GFETs, such as gas or chemical sensing or infrared imaging.
