Hi,
Instead of using any particular IC, I would use the cheap electonic consisting of high brightness LED and a LDR place exactly face to face.
When their would be no interrruption between the LED and LDR, complete light falls on the LDR decreasing the resistance of the LDR.
When their would be any interruption (smoke) in the path this would led to less energy fall on LDR raising its resistance.
So you could detect the voltage change due to change in resistance.