Provided are a near-infrared II polymer fluorescent sub-microsphere and a method for preparing the same. The method includes steps of 1) dissolving fluorochrome in a water-immiscible organic solvent, thus obtaining a fluorochrome solution; 2) distributing a polymer sub-microsphere into a sodium dodecyl sulfonate solution, thus obtaining a sub-microsphere solution with the polymer sub-microsphere as a carrier for the fluorochrome; 3) subjecting a first mixture of the fluorochrome solution and the sub-microsphere solution to ultrasonic treatment, thus obtaining an emulsion; 4) swelling the emulsion such that the fluorochrome solution enters nanopores formed during swelling of the polymer sub-microsphere, thus obtaining a second mixture; and 5) heating the second mixture to volatilize the organic solvent, such that the fluorochrome is crystallized out and encapsulated in the nanopores, thus obtaining the near-infrared II polymer fluorescent sub-microsphere.

Nanodiamonds are grown under conditions where diamond-like organic seed molecules do not decompose. This permits engineered growth of fluorescent nanodiamonds wherein a custom designed seed molecule can be incorporated at the center of a nanodiamond. By substituting atoms at particular locations in the seed molecule it is possible to achieve complex multi-atom diamond color centers or even to engineer complete quantum registers. In addition, it is possible to grow ultra-small nanodiamonds, wherein each nanodiamond, no matter how small, can have at least one bright and photostable fluorescent emitter.

Nanodiamonds are grown under conditions where diamond-like organic seed molecules do not decompose. This permits engineered growth of fluorescent nanodiamonds wherein a custom designed seed molecule can be incorporated at the center of a nanodiamond. By substituting atoms at particular locations in the seed molecule it is possible to achieve complex multi-atom diamond color centers or even to engineer complete quantum registers. In addition, it is possible to grow ultra-small nanodiamonds, wherein each nanodiamond, no matter how small, can have at least one bright and photostable fluorescent emitter.

Methods of making graphene quantums dots are provided. The methods can produce graphene quantum dots with a monodisperse size distribution. The graphene quantum dots are produced, via one-pot synthesis, from a graphene source and a strong oxidizing mixture at an elevated temperature. The strong oxidizing mixture can contain one or more permanganates and one or more oxidizing acids. Exemplary permanganates include sodium permanganate, potassium permanganate, and calcium permanganate. Exemplary oxidizing acids include nitric acid and sulfuric acid. The graphene quantum dots can have an average particle size of between about 1 nm and 20 nm and a monodisperse size distribution. For example, the size distribution can have a span about 1 or less and/or a coefficient of variance of about 0.5 or less. About 40% or more of the graphene quantum dots can have a diameter within ±5 nm of the average particle size of the graphene quantum dots.

The present invention is directed to a method of preparing a carbon quantum dot. The carbon quantum dot can be prepared from a carbon precursor, such as a fullerene, and a complex metal hydride. The present invention also discloses a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride and a polymer containing a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride.

The present invention is directed to a method of preparing a carbon quantum dot. The carbon quantum dot can be prepared from a carbon precursor, such as a fullerene, and a complex metal hydride. The present invention also discloses a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride and a polymer containing a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride.

Provided is a hybridized perovskite quantum dot material. The quantum dot material comprises a kernel and surface ligands. The kernel is formed by R.sub.1NH.sub.3AB.sub.3 or (R.sub.2NH.sub.3).sub.2AB.sub.4, where R.sub.1 is methyl group, R.sub.2 is an organic molecular group, A is at least one selected from Ge, Sn, Pb, Sb, Bi, Cu and Mn, B is at least one selected from Cl, Br and I, A and B form a coordination octahedral structure, and R.sub.1NH.sub.3 or R.sub.2NH.sub.3 is filled in gaps of the coordination octahedral structure. The surface ligand is an organic acid or organic amine. The quantum dot material has a high fluorescence quantum yield.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

An aerogel fabricated by forming an aqueous suspension including carbon nanotubes and a surfactant, agitating the aqueous suspension, and centrifuging the agitated suspension to form a supernatant including the carbon nanotubes. The supernatant is concentrated to form a concentrated suspension including the carbon nanotubes, and a hydrogel is formed from the concentrated suspension. The hydrogen is contacted with a strong acid to form an acidic hydrogel and to remove surfactant from the hydrogel, and then neutralized. An aerogel is formed from the hydrogel. The aerogel may consist essentially of carbon nanotubes. A composite may be formed from the hydrogel or the aerogel by infiltrating the hydrogel or the aerogel with a polymeric material and curing or pyrolyzing the polymeric material. The composite may be electrically conductive, transparent, flexible, superelastic, or any combination thereof. A device, such as a flexible conductor, sensor, or electrode may include the aerogel or the composite.