Fig. 1: Schematic illustration of the concept of the cytokine sensor operation.
From: Ultrasensitive rapid cytokine sensors based on asymmetric geometry two-dimensional MoS2 diodes
a A small volume of blood serum is drop casted onto the sensing area. b The cytokine sensor consists of an asymmetric geometry MoS2 crystal contacted by two metal electrodes. The inset shows a magnified diagram of the sensing area showing how TNF-α cytokines are bound to aptamer receptors on the oxide, forming G-quadruplex structures and bringing charged cytokines closer to the surface of the sensor. c The change in surface charge density induces a change in the electrical rectification behavior of the MoS2 diode observed in a current–voltage (I–V) measurement.
