Dai-Wen Pang and colleagues from Wuhan University have developed a new way of making core/shell multifunctional nanocrystals with tuneable fluorescence emission and magnetic properties.  The nanocrystals are made up of a magnetic cobalt-platinum nanoparticle core, within a fluorescent cadmium-selenium shell. These properties open up potential applications in bio-labelling and imaging in biomedicine.  'Tuning the multicolour fluorescence emission of fluorescent-magnetic multifunctional nanoparticles paves the way towards simultaneous rapid preconcentration and detection of different viruses and bacteria and multimodal cancer diagnosis,' says Pang. 

Existing materials of this type usually possess at least one short-coming, such as untuneable fluorescence emission, large size and poor stability.  Pang has shown that these multifunctional nanocrystals have remarkable advantages, such as a wide tuneable photoluminescence range, they are small in size, have a core/shell structure and can be easily reproduced.  

Pang explains that 'the future development of this work lies in two major directions; one is to focus on preparation of near-infrared fluorescent-magnetic multifunctional nanocrystals in order to realize the fluorescent-magnetic multimodal imaging of tissues deep in body. The second direction is to develop fluorescent-magnetic multifunctional nanocrystals with low toxicity and good biocompatibility.' 

Therefore the main challenge for future research in this area is to achieve nanocrystals with higher quantum yields that continue to have a colour-tuneable fluorescence and magnetic functionality.  

Mary Badcock