Fig. 6: Incorporation of DEP trapping in the QMT sensors for the molecular detection at ultralow concentration. | Nature Communications

Fig. 6: Incorporation of DEP trapping in the QMT sensors for the molecular detection at ultralow concentration.

From: Combined quantum tunnelling and dielectrophoretic trapping for molecular analysis at ultra-low analyte concentrations

Fig. 6

a Fluorescence imaging of the nanoprobe under application of an AC DEP trapping voltage for fluorescently labelled beads, lambda DNA and proteins. (i) control experiment without applied AC voltage. b Tunnelling current traces of a typical DEP (Vpp 10 V, fAC 100 kHz, 10 s) pre-concentration/detection cycle for detection of 1 fM poly-A20. c Typical conductance time traces for 1 fM poly-A20 at different AC trapping voltages. Normalised histograms of the conductance and AC frequency fAC = 100 kHz, and trapping time of 10 s before performing tunnelling measurements at an applied DC bias of 50 mV. d Analysis of improvement in event rates as a function of DEP voltage and frequency. Event rate vs AC voltage was measured at fAC 100 kHz, Event rate vs AC frequency was measured at AC voltage of 10 Vpp. e, f Event rate for the detection of poly-A20 and streptavidin when compared to performing measurements with and without DEP. All error bars represent 1 standard deviation from the mean.

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