Thermo-mechanical properties and optimization of sodium alginate as a polymer backbone substrate for biosensor application

This study was aim to optimize the formulation of the sodium alginate biosensor substrate with incorporation of sodium alginate (1%-6%(w/v)) as a polymer backbone and glycerol (10–50 wt%) as a plasticizer. The effect of their interaction on film's tensile strength (TS) and elongation at break (EB) were analyzed via response surface methodology-central composite design (RSM-CCD). The optimum parameter of the films for the maximum TS was at 1.90%(w/v) of sodium alginate and 17 wt% of glycerol and for maximum EB was at 4.89%(w/v) of sodium alginate and 49.65 wt% of glycerol. The optimum parameter of the films had revealed the better TS was at lower sodium alginate content and better EB was at higher glycerol content. In terms of thermal stability, the thermal decomposition temperature (T_onset) of sodium alginate decreased with the incorporation of glycerol.