Label-Free CMOS DNA Quantification with On-Chip Noise Reduction Schemes

We present a label-free CMOS DNA sensor with a new sensing-pixel architecture and background noise reduction scheme. The proposed sensor generates a differential signal between bio-samples and reference buffer solution with significant reduction in offset and gain fixed pattern noise by employing on-chip correlated double sampling circuits. Non-surface-binding detection technique allows to quantify DNA molecules continuously and sequentially and to reuse the sensor by simple washing protocol. By directly reading the negative charges of DNA molecules, DNA concentrations from 1 muM to 10 muM have been successfully discriminated.