Quantitative nanoscale field effect sensors

Figures & data

Figure 1. Scanning electron micrograph of a completed nanowire bioFET device showing characteristic trapezoidal cross section due to anisotropic etch [23].

Figure 2. Microfluidic purification chip (MPC) consisting of honeycomb structure of silicon pillars used by Stern et al. for capture-release filtration of whole blood. (a) Primary antibodies are immobilised on the MPC via photocleavable crosslinker. (b) Whole blood is added to the MPC allowing the binding of specific antigens to the MPC surface. Washing step includes substitution of the whole blood with a buffer solution with low-ionic concentration. (c) UV-exposure allows release of immobilised antibody-antigen complexes into the buffer solution. (d) In the last step, the buffer solution with antibody-antigen complexes is transferred to functionalised nanoribbon chip where the detection occurs [26].

Figure 3. Average threshold voltage dependence of nanoribbonbioFET as a function of its position on a 4” wafer [29].

Figure 4. Initial current rate of five devices from the same die recorded simultaneously as a function of both baseline currents and device solution transconductances at and . The relative standard deviations for initial current rates, baseline currents and tranconductances are 0.7%, 0.3% and 0.6%, respectively. Both fits are linear (y = kx) shown on a log–log scale for clarity [29].

Figure 5. Calibration curves for (a) PSA and (b) CA15.3 show linear device response in the clinically relevant range of analytes. Circular data point represents a blind measurement [29].

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Vacic A, Criscione JM, Stern E, Rajan NK, Fahmy T, Reed MA. Multiplexed SOI BioFETs. Biosens Bioelectron. 2011;28:239–242.

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