Analyte accumulation device
View Patent ↗A device for accumulation of vapor analytes incorporating nanotubes grown by CVD is described. The devices are used in sensors and as a preconcentrator for a gas chromatograph.
1. A method for the accumulation of an analyte as a vapor or gas and detection by a detection means which comprises:
(a) providing a preconcentrator device with a heater structure which comprises (a) a non-conductive substrate in a container means having an opening for inlet of the analyte and an outlet for the analyte; a conductive strip bound to the substrate; a strip of a metal catalyst, which allows growth of nanotubes, mounted on the conductive strip; and (d) a lawn of carbon nanotubes which have been grown by chemical vapor deposition on the strip of the metal catalyst, wherein the nanotubes are adapted to accumulate the analyte inside the container means;
(b) introducing the analyte into the container means through the inlet means so as to accumulate the analyte in the carbon nanotubes;
(c) heating the nanotubes in the preconcentrator device with the heater structure to remove the analyte from the nanotubes in the container means through the outlet; and
(d) detecting the gas analyte with the detection means.
2. The method of claim 1 wherein the detecting is with a gas chromatograph.
3. The method of claim 1 wherein the detecting means is a gas sensor means.
4. The method of claim 1 wherein the strip of the catalyst is a transition metal, the conductive strip is a metal, a conductor or semiconductor, and the substrate is a semiconductor or insulator.
5. The method of claim 1 wherein the substrate is a plate with a series of channels with the carbon nanotubes in the channels.
6. The method of any one of claims 1 , 2 , 3 , 4 or 5 wherein the device is a MEMS device, wherein a surface area of the conductive strip is in the range of about 50 millimeters 2 or less.