Surface plasmon resonance (SPR) sensor technology has great potential for many applications. In addition, protein immobilisation is a critical step in the production of protein biochips, biosensors, etc. Here, the vapour-phase silanisation with 3-aminopropyltriethoxysilane (APTES) of the SPR response of a thin silver film (50 nm) has been considered. The obtained data were correlated with the morphology, absorbance, stability and water contact angle of the composites to observe the coating mechanism. The identification of an approach for determining the amine accessibility and stability of the silver surfaces that are coated with amino-organic films is the main outcome of this study. The results illustrate that the surface property of the silver layer can be changed using these methods. The evaluation of the amine accessibility verifies that all prepared chips can effectively assist in protein immobilisation on silver-coated slides. Comparing various studied silanisation conditions (different times, temperatures and APTES concentrations), it is concluded that silanisation at 80°C for 30 min is a simple and efficient method for protein immobilisation on silver-coated glass slides, which has potential application in the production of protein chips and biosensors.