Dodecylamine dialdehyde starch (DASDA) is synthesized with corn starch, sodium periodate, and dodecylamine, and its structure, particle morphology, crystal structure, and thermal properties are characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. Antibacterial activity against Escherichia coli and Staphylococcus aureus suggests that minimum inhibitory concentrations of DASDA against E. coli and S. aureus are 0.31 and 0.63 mg mL −1 , and the antibacterial effect against E. coli is better than that against S. aureus. The antibacterial activity is effectively improved with the increase of amino content of DASDA.

Carboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) and its metal complexes were synthesized by corn starch (St), sodium periodate, carboxymethyl chitosan and metal ions (copper, zinc, nickel, silver), and were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), energy dispersive spectroscopy (EDS) and X-ray powder diffraction (XRD). The antibacterial activities of CMCDAS against E. coli and S. aureus increased according with its increasing nitrogen content, and the best minimum inhibitory concentrations (MIC) to E. coli and S. aureus were 30 mg/mL, respectively. Furthermore, the minimum inhibitory concentrations (MIC) of the metal Complexes (copper, nickel, silver, and zinc) against S. aureus were 7.50 mg/mL, 30 mg/mL, 30 mg/mL, and 1.88 mg/mL, respectively; and against E. coli were 7.50 mg/mL, 15 mg/mL, 15 mg/mL, and 0.94 mg/mL, respectively.