HI, is there any bus going from HKIA to Zhuhai - Gongbei?? thanks

Yes, there are several direct shuttle buses from from HKIA to Zhuhai Gongbei port. The Ticket fare is 234 HKD /person, and the duration time is 4 hours. Departure time: 09:10, 13:10, 14:10, 14:55, 17:10, 18:55 and 19:50.

In addition, you may also take boat for about 70 minutes to reach the Jiuzhou Port, and the general class is 290HKD/person. Then, you can catch bus line 4 for 20 minutes to reach your destination. Ticket fare is CNY4/person.
You can choose the way you like. :)