Abstract: One aspect of the invention provides an imaging method including: (a) acquiring a first fluorescent image of an object of interest impregnated with fluorescent nanodiamonds; (b) applying a magnetic field to the fluorescent nanodiamonds in order to decrease fluorescence of the fluorescent nanodiamonds; (c) acquiring a second fluorescent linage of the object of interest; and (d) subtracting the second fluorescent linage from the first fluorescent image to produce a resulting image. Another aspect of the invention provides an imaging method including: (a) applying a time-varying magnetic field to an object of interest impregnated with fluorescent nanodiamonds to modulate the fluorescence of the fluorescent nanodiamonds; (b) acquiring a plurality of fluorescent images of the object of interest; and (c) for each corresponding pixel in the plurality of fluorescent images, calculating a fluorescence intensity using a lock-in technique.

Abstract: A method of increasing a density of carboxylic acids on a surface of a carbon nanoparticle is disclosed. The method includes contacting an oxygen-containing functional group on a surface of a carbon nanoparticle with a reducing agent to provide a hydroxyl group; reacting the hydroxyl group with a diazoacetate ester in the presence of a transition metal catalyst to provide an ester, the diazoacetate ester having the structure wherein R is a C1-8 hydrocarbyl, preferably tert-butyl, methyl, ethyl, isopropyl, allyl, benzyl, pentafluorophenyl, or N-succinimidyl; and cleaving the ester to provide a carboxylic acid group. Surface-functionalized carbon nanoparticles made by the method are also disclosed.

Abstract: A method of preparing a polydopamine-coated nanodiamond includes contacting a nanodiamond with dopamine in an alkaline aqueous solution under conditions effective to form a polydopamine-coated nanodiamond. A method of functionalizing a nanodiamond includes preparing a polydopamine-coated nanodiamond; and covalently coupling a compound comprising a functional group to the polydopamine of the polydopamine-coated nanodiamond. A nanodiamond prepared by the methods is also disclosed.

Abstract: A method of increasing a density of carboxylic acids on a surface of a carbon nanoparticle is disclosed. The method includes contacting an oxygen-containing functional group on a surface of a carbon nanoparticle with a reducing agent to provide a hydroxyl group; reacting the hydroxyl group with a diazoacetate ester in the presence of a transition metal catalyst to provide an ester, the diazoacetate ester having the structure wherein R is a C1-8 hydrocarbyl, preferably tert-butyl, methyl, ethyl, isopropyl, allyl, benzyl, pentafluorophenyl, or N-succinimidyl; and cleaving the ester to provide a carboxylic acid group. Surface-functionalized carbon nanoparticles made by the method are also disclosed.

Abstract: Imaging systems and methods using fluorescent nanodiamonds are disclosed. The imaging systems and methods including applying a time-varying magnetic field to a specimen containing fluorescent nanodiamonds and comparing the fluorescence obtained with different magnetic fields to provide an image of the specimen.

Abstract: Fiducial marker compositions comprising fluorescent nanodiamonds and methods of making and using the fiducial marker compositions are disclosed. The fiducial marker composition comprises a substrate, and a fluorescent nanodiamond immobilized on a surface of the substrate, wherein the substrate and immobilized fluorescent nanodiamond are optionally top coated with an inert top coating. The fiducial marker compositions are used in imaging methods to correct for drift and other alignment instabilities, and are particularly useful in super-resolution imaging.

Abstract: Imaging systems and methods using fluorescent nanodiamonds are disclosed. The imaging systems and methods including applying a time-varying magnetic field to a specimen containing fluorescent nanodiamonds and comparing the fluorescence obtained with different magnetic fields to provide an image of the specimen.

Abstract: One aspect of the invention provides an imaging method including: (a) acquiring a first fluorescent image of an object of interest impregnated with fluorescent nanodiamonds; (b) applying a magnetic field to the fluorescent nanodiamonds in order to decrease fluorescence of the fluorescent nanodiamonds; (c) acquiring a second fluorescent linage of the object of interest; and (d) subtracting the second fluorescent linage from the first fluorescent image to produce a resulting image. Another aspect of the invention provides an imaging method including: (a) applying a time-varying magnetic field to an object of interest impregnated with fluorescent nanodiamonds to modulate the fluorescence of the fluorescent nanodiamonds; (b) acquiring a plurality of fluorescent images of the object of interest; and (c) for each corresponding pixel in the plurality of fluorescent images, calculating a fluorescence intensity using a lock-in technique.

Abstract: One aspect of the invention provides an imaging method including: (a) acquiring a first fluorescent image of an object of interest impregnated with fluorescent nanodiamonds; (b) applying a magnetic field to the fluorescent nanodiamonds in order to decrease fluorescence of the fluorescent nanodiamonds; (c) acquiring a second fluorescent image of the object of interest; and (d) subtracting the second fluorescent image from the first fluorescent image to produce a resulting image. Another aspect of the invention provides an imaging method including: (a) applying a time-varying magnetic field to an object of interest impregnated with fluorescent nanodiamonds to modulate the fluorescence of the fluorescent nanodiamonds; (b) acquiring a plurality of fluorescent images of the object of interest; and (c) for each corresponding pixel in the plurality of fluorescent images, calculating a fluorescence intensity using a lock-in technique.

Abstract: One aspect of the invention provides an imaging method including: (a) acquiring a first fluorescent image of an object of interest impregnated with fluorescent nanodiamonds; (b) applying a magnetic field to the fluorescent nanodiamonds in order to decrease fluorescence of the fluorescent nanodiamonds; (c) acquiring a second fluorescent image of the object of interest; and (d) subtracting the second fluorescent image from the first fluorescent image to produce a resulting image. Another aspect of the invention provides an imaging method including: (a) applying a time-varying magnetic field to an object of interest impregnated with fluorescent nanodiamonds to modulate the fluorescence of the fluorescent nanodiamonds; (b) acquiring a plurality of fluorescent images of the object of interest; and (c) for each corresponding pixel in the plurality of fluorescent images, calculating a fluorescence intensity using a lock-in technique.