Polysiloxane-polyvinyl alcohol discs as support for antibody immobilization: Ultra-structural and physical-chemical characterization

A semi-interpenetrated polymer network of posiloxane and polyvinyl alcohol (POS-PVA) was synthesized through sol-gel process in the form of discs and used as solid support for antibody immobilization. POS-PVA discs presented a protein loading capacity of approximately 210 μg/disc and can covalently bind an anti-S100 protein antibody via glutaraldehyde. The POS-PVA matrix network resulted in hard and spherical discs of uniform size, diameter of 4.0 mm2. Scanning electron microscopy (SEM) analysis revealed a uniformly formed porous network. The SEM and infrared absorption spectra confirmed that the activation with glutaraldehyde do not alter the POS-PVA discs structure is similar to that discs before antibody immobilization. The elemental analysis of discs (POS-PVA + Glutaraldehyde + Antibody) was evaluated and the following constitution was obtained (%): carbon (6.57), nitrogen (0.67), hydrogen (4.25) and sulphur (0.32), suggesting that the antibody completely fixed after adsorption. The shelf-life of discs was performed at six months and showed better protein loading capacity by POS-PVA discs incubated at 4 °C and hydrated with phosphate buffer solution when compared with same discs exposed to different environment store (room temperature and dry). In conclusion, microarrays of antibody immobilized on POS-PVA support demonstrated sensitivity, its antibody covalent immobilization and discs synthesis involves simple steps and the reagents employed are inexpensive. Hence the present semi-interpenetrating polymer network can be used as an alternative of solid support for sera assays.