Disclosed is an antibacterial composition comprising titanium oxide particles immobilized with an antibody having affinity and cognitive power to a microorganism of interest, and a method for sterilizing the microorganism by using the same. In particular, the present invention relates to a method for preparing functional titanium oxide particles capable of recognizing a microorganism or a virus of interest, and a method for selectively and efficiently sterilizing the same by using the functional titanium oxide particles, and not for randomly sterilizing microorganisms or viruses by using conventional titanium oxide particles having no recognition power to a microorganism or a virus of interest.
