  We report the dispersive charge-state readout of a double quantum dot in the
few-electron regime using the in situ gate electrodes as sensitive detectors.
We benchmark this gate-sensing technique against the well established quantum
point contact (QPC) charge detector and find comparable performance with a
bandwidth of 10 MHz and an equivalent charge sensitivity of 6.3 x 10-3 e/ \sqrt
Hz. Dispersive gate-sensing alleviates the burden of separate charge detectors
for quantum dot systems and promises to enable readout of qubits in scaled-up
arrays.
