getting sender object in cocos2d

I am making a game using cocos2d. By using the following code,I have added an animation.How do I send the CCSprite reference?

if(sprite != monkey)
{
    [self scheduleOnce:@selector(animate_sprite:) delay:0.1f];
}

-(void)animate_sprite:(ccTime) dt
{
    id s2 = [CCScaleTo actionWithDuration:0.5 scaleX:2.0 scaleY:2.0];
    id fun = [CCCallFuncN actionWithTarget:self selector:@selector(spriteDone:)];
    [sprite runAction:[CCSequence actions:s2,fun,nil]];
}

How to get the sprite reference in animate_sprite method?

You can use performSelector:withObject:afterDelay this will do the same thing.

if(sprite != monkey)
{
    [self performSelector:@selector(animate_sprite:) withObject:sprite afterDelay:0.1f];
}

-(void)animate_sprite:(CCSprite *)sprite
{

    id s2 = [CCScaleTo actionWithDuration:0.5 scaleX:2.0 scaleY:2.0];
    id fun = [CCCallFuncN actionWithTarget:self selector:@selector(spriteDone:)];
    [sprite runAction:[CCSequence actions:s2,fun,nil]];
}

So just edit your method to use the sprite and not the ccTime object since you are not using it at all.