Superhydrophobic lab-on-chip measures secretome protonation state and provides a personalized risk assessment of sporadic tumour

Super-hydrophobic chip incorporates five gold electrodes in a line for site-selective measurements of a solution (a). Individual silicon micropillars are modified to incorporate gold nano-electrodes, an intermediate layer of C4F8 and a superficial layer of the conductive PEDOT:PSS polymer, bar in the inset is 5 μm (b). Sensors are positioned from the centre (S3) to the border (S1, S5) of the device; the output of each sensor is a function of time I(t) that reaches a constant value in a characteristic time τ; the intensity of I is proportional to the externally applied voltage V (c). Convenient post-processing of a sample enables super-hydrophobicity with contact angles as large as 165° (d). SEM micrographs of the device magnified at small magnification factors (e). SEM micrograph of the device shows the gold nano-electrodes positioned on the pillar surface for localized sensing (f). Due to super-hydrophobicity, biological solutions can be manipulated and connected to an external gate during operation (g). The images were partially adapted from https://www.nature.com/articles/srep18992 1