When nicotine receptors will be gone after quitting smoking?

Got it backwards : Nicotine (nicotinic) receprors are so named because they have an affinity for bonding with nicotine. That's where nicotine exerts its effects. They were there before you started using nicotine, and will be there after you stop. Think of any other receptor site that has an affinity for a specific biochemical (serotonin, dopamine, endorphin, acetylcholine, gaba, etc).