Hull City midfielder Jimmy Bullard is also being lined up by Hoops boss Neil Lennon.
Brown said: "I've seen in the papers we are trying to get Sol Campbell and Jimmy Bullard and they seem interested so that's good for us.
"They've just got to come and see the fans and this place when it's full. Old Firm games as well. I think everybody remembers them because the atmosphere is scary. The hairs on the back of your neck stick up. You gte pins and needles.
"It's a weird feeling when all the Celtic fans are singing. There are 10,000 Rangers fans and you can't even hear them. If these guys come and see that, they will see it is a special place. We are one of the biggest clubs in the world.
"I know we don't have the financial power of the Premier league but as far as fan base is concerned we must be up there."