The rapid development of surface sensitive biosensor technologies requires optimum control of surface modification to provide reliable and reproducible results. With the aim to assemble a quartz crystal microbalance (QCM)-based protein biosensor, we focus our attention on sulfide receptor and its integration with the surface of the electrode. Here, we present different surface modification processing time to allow sulfide molecules to be immobilized to gold coated sensor for QCM sensing. The optimum surface modification processing time is also obtained by bovine serum albumin (BSA) binding measurement.