Disclosed herein is a compound having a structureor a pharmaceutically acceptable salt, prodrug, or bioisostere thereof. The photodiodes include a first optical waveguide having a tapered first end, a second optical waveguide having a tapered second end, and at least one nanowire comprising at least one semiconductor material connecting the first and second ends in a bridging configuration. The exhaust gas sensor further includes a NOx Nernst cell that generates a second voltage indicative of a NOx concentration in the exhaust gases communicating with the NOx sensing electrode. The pixel images converted by the digital camera are input to a computer system. The body further supports a movable bumper mouth and movable eyes and eyebrows behind the windshield.