As a potential biomarker, Platelet-Derived Growth Factor (PDGF) has been directly implicated with vascular disorders and malignant diseases such as cancers, glioblastomas and sarcomas. To realise sensitive and reliable detection of PDGF, Electrochemical Proximity Assay (ECPA) was employed. ECPA is an extremely flexible and sensitive strategy for protein recognition. In our previous work, a SPR/Fluorescence Spectroelectrochemical System (SFSS) was developed, integrating Surface Plasmon Resonance (SPR), Surface Plasmon Fluorescence and electrochemical spectroscopy. SFSS is able to enhance the power of surface characterization techniques, through cross-validation and compensation among all three techniques. Here, we took advantage of SFSS to explore on the ECPA of PDGF-BB. Through proper tags, we are able to recognise the signals from different components, observe the real-time binding dynamics of components occurring on biosensor interface, and estimate their surface coverages. SFSS has helped us deepen our understanding for ECPA into an unprecedented level, and improve its sensitivity and reliability on the detection of PDGF-BB.