Dr James Hainfeld gained a bachelor's degree in electrical engineering from Princeton University in 1967 and then proceeded to study for a Ph.D in biochemistry at the University of Texas at Austin. For the next few years he undertook further biochemistry research, first at the University of Chicago and later at the Brookhaven National Laboratory. In 1990, whilst still at Brookhaven, he became President of Nanoprobes Incorporated, a company specialising in research and development relating to immuno-labelling and immunoassay tests. To date James Hainfeld has published well over 130 papers in these fields and he has undertaken editorial duties for several American publications. He is also Adjunct Professor at the State University of New York.

In 2006 Dr Hainfeld and three colleagues (Drs Slatkin, Focella and Smilowitz) published in the BJR an article entitled "Gold nanoparticles: a new x-ray contrast agent". The paper attracted immediate worldwide interest and has a citation record which is far ahead of any other BJR article from the same period. This was the first published report showing that gold nanoparticles could overcome several of the practical and clinical limitations known to exist with other contrast agents and the article prompted much subsequent research in the field. As the BJR was effectively the launch pad for this major international development, and which itself brings together several scientific and clinical disciplines, it is highly fitting that Dr Hainfield and his colleagues should be chosen to be the recipients of the Röntgen Prize for 2011