A method for producing nanoscale titanium dioxide particles which are coated with an oxide, a hydroxide or an oxide hydroxide of Al, Ce, Zr and/or Si wherein the enzymatic precipitant system urease/urea is used. Said coated titanium dioxide particles can have an average size of less than 50 nm, the coating providing effective protection against photocatalytic reactions. The coated particles are suitable, in particular, as UV absorbers in a transparent organic matrix.