The current disclosure, in one embodiment, includes a polysaccharide conjugate. This conjugate has a polysaccharide and at least one monomeric amino acid having an O-group covalently bound to the polysaccharide. The conjugate also has at least one metal conjugated by the O-group of the amino acid. According to another embodiment, the disclosure provides a method of synthesizing a polysaccharide conjugate by covalently bonding a monomeric amino acid having an O-group to a polysaccharide and by conjugating a metal to the O-group to form a polysaccharide conjugate. According to a third embodiment, the disclosure relates to a method of killing a cancer cell by administering to the cell an effective amount of a polysaccharide conjugate. This conjugate has a polysaccharide and at least one monomeric amino acid having an O-group covalently bound to the polysaccharide. The conjugate also has at least one metal conjugated by the O-group of the amino acid.