Smoke Sensor Circuit

I am a new student in electrical engineering. I am planing to build a smoke sensor circuit. I will be grateful if anybody can supply me a list of the required parts along with the schematics.

Those parts are not any off-the-shelf set. For instance, there is more than one way of detecting smoke. Will the detector be battery or line powered? How will it indicate the alarm. Whose standards for safety must it fulfill?

As a student, you get good experience in searching for such information.

Here is a simple differential circuit, and the parts should be easy to find.

http://www.circuit-projects.com/miscellaneous/ldr-a-led-pair-smoke-detector-and-alarm-by-lm1801.html

Modern units are available cheap at KMart, Walmart... You have to follow the traces to produce a schematic, dismantle it desoldering everything and you will have ALL the parts to put one together again and learn something in the process.
If your intended 'sensor' is not exactly 'detection' as in those domestic alarms, modifying them to get readings instead of beeping may be another learning opportunity.
Miguel

thanks for the advise and link. hope i will get more help regarding this matter..