Enhanced magnetic behavior, exchange bias effect, and dielectric property of BiFeO3 incorporated in (BiFeO3)0.50 (Co0.4Zn0.4Cu0.2 Fe2O4)0.5 nanocomposite AIP Advances 4, 037112 (2014) Second Harmonic Generation (SHG) from BiFeO 3 nanocrystals is investigated for the first time to determine their potential as biomarkers for multiphoton imaging. Nanocrystals are produced by an auto-combustion method with 2-amino-2-hydroxymethyl-propane-1,3-diol as a fuel. Stable colloidal suspensions with mean particle diameters in the range 100-120 nm are then obtained after wet-milling and sonication steps. SHG properties are determined using two complementary experimental techniques, Hyper Rayleigh Scattering and nonlinear polarization microscopy. BiFeO 3 shows a very high second harmonic efficiency with an averaged hdi coefficient of 79 6 12 pm/V. From the nonlinear polarization response of individual nanocrystals, relative values of the independent d ij coefficients are also determined and compared with recent theoretical and experimental studies. Additionally, the particles show a moderate magnetic response, which is attributed to c-Fe 2 O 3 impurities. A combination of high nonlinear optical efficiency and magnetic response within the same particle is of great interest for future bio-imaging and diagnostic applications. V C 2014 AIP Publishing LLC.[http://dx