A method of distinguishing cancerous cells and healthy cells of a subject from each other comprises the steps: (i) contacting a region of tissue of a subject suspected of including at least some cancer cells with a plurality of nanodiamonds, wherein the plurality of nanodiamonds comprise a first plurality of conjugates, wherein the conjugates of the first plurality of conjugates consist of first nanodiamonds and one or more cancer cell targeting agents, wherein the first nanodiamonds have a first type of colour center, and a second plurality of conjugates, wherein the conjugates of the second plurality of conjugates consist of second nanodiamonds and one or more healthy cell targeting agents, wherein the second nanodiamonds have a second type of colour center； and (ii) applying light of a first wavelength so as to excite the first type of colour center and applying light of a second wavelength so as to excite the second type of colour center, wherein upon contacting the region of tissue with the plurality of nanodiamonds, cancer cells are adhered to the first plurality of conjugates, and healthy cells are adhered to the second plurality of conjugates； wherein upon applying light to the region of tissue, the colour centers of the nanodiamonds of the first plurality of conjugates adhered to cancer cells emit fluorescence at a first wavelength, and the colour centers of the nanodiamonds of the second plurality of conjugates adhered to healthy cells emit fluorescence at a second wavelength； and wherein the colour contrast between the two wavelengths and the positions of respective conjugates delineate the area of cancer cells and the area of healthy cells from each other.L'invention concerne un procédé de distinction mutuelle de cellules cancéreuses et de cellules saines d'un sujet l'un comprenant les étapes suivantes : (i) mettre en contact une région de tissu d'un sujet suspecté de porter au moins certaines cellules cancéreuses avec une pluralité de nanodiamants, la p
