A recent article in OnOrbit described a proof of concept that was developed by Jing Li, a scientist at Ames, and a group of other researchers. In order to test out the tiny nanosensor-based chemical sensing circuitry, Li and his team created a device that plugs into the dock port of an iPhone.
To quote the original post,
A newer version of the sensor has 64 nanosensors built-in and is less than 1 cm on a side. Isn't it cool that your iPhone is getting to be more like a Star Trek tricorder every day?The new device is able to detect and identify low concentrations of airborne ammonia, chlorine gas and methane. The device senses chemicals in the air using a "sample jet" and a multiple-channel silicon-based sensing chip, which consists of 16 nanosensors, and sends detection data to another phone or a computer via telephone communication network or Wi-Fi.