Diagnosis of breast cancer recurrence after surgery by using poly(2-dimethylaminoethyl methacrylate) brushes as a medium on silicon surface

We have grafted pH-responsive tethered poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) onto silicon surfaces through atom transfer radical polymerization (ATRP) as a medium to extract human genomic DNAs (gDNAs) from a biological specimen, namely human blood incorporating target DNA (bcrDNA584; a DNA genomic disease index of breast cancer, that could be useful for the rapid diagnosis of breast cancer recurrence after surgery) and control DNA (hgDNA528) at concentrations of 0.05, 0.1, and 0.2 ng μL−1. After amplifying the signal of the bcrDNA584 and hgDNA528 strands released from the tethered PDMAEMA on the substrate using the polymerase chain reaction (PCR), we identified these gDNAs using agarose gel electrophoresis. The accuracy of the detection of bcrDNA584 and hgDNA528 was controlled through the design of specific primers in the PCR process. The quantities of these two gDNAs obtained through the capture and release from tethered PDMAEMA brushes under pH tuning conditions were sufficient for them to be amplified recognizably, suggesting that this approach could be used in miniaturized lab-on-a-chip cartridges for rapid disease diagnosis.