【Abstract】 In the solution containing ammonia,silver nitrate was reduced by tartaric acid,and nano-silver colloids were generated.The products were characterized by transmission electron microscope(TEM) and X-ray diffraction(XRD).The results show that the average size of silver colloid particles is 25-30 nm and the shape is near-spherical.Researches on the character of resonance light scattering(RLS) of nano-silver colloid indicates that the strongest RLS peak of nano-silver colloid appeares at 447 nm.When BSA adding into the nano-silver colloid solution,the RLS peaks intensity was quenched.Based on this,a novel and simple method of determination of BSA was developed.Under optimum conditions,the linear response is over the range of 2.5pg/mL～2.5×106 pg/mL.更多还原