Abstract: Disclosed is DNA valency sorting chromatography, a purification method for separating solutes based on the number of barcoded DNA molecules present on their surface, which can operate using conventional low-pressure chromatography equipment and instrumentation. Solutes can take a variety of forms, including biological macromolecules, polymeric nanoparticles, gold or silver nanospheres, gold nanorods, iron oxide nanoparticles, and semiconducting nanocrystals. In contrast to most existing purification procedures, DNA valency sorting is highly selective for the DNA sequence specifically, rather than the characteristics of the solute as a whole, and uses extremely gentle elution conditions. As a result, it is applicable to a range of solute characteristics, including variable chemical composition, surface charge, and materials with hydrodynamic diameters up to 80 nm, which cannot be purified with a well-defined number of macromolecules by any other existing technique.

Abstract: Novel Mn2+-doped quantum dots are provided. These Mn2+-doped quantum dots exhibit excellent temperature sensitivity in both organic solvents and water-based solutions. Methods of preparing the Mn2+-doped quantum dots are provided. The Mn2+-doped quantum dots may be prepared via a stepwise procedure using air-stable and inexpensive chemicals. The use of air-stable chemicals can significantly reduce the cost of synthesis, chemical storage, and the risk associated with handling flammable chemicals. Methods of temperature sensing using Mn2+-doped quantum dots are provided. The stepwise procedure provides the ability to tune the temperature-sensing properties to satisfy specific needs for temperature sensing applications. Water solubility may be achieved by passivating the Mn2+-doped quantum dots, allowing the Mn2+-doped quantum dots to probe the fluctuations of local temperature in biological environments.

Abstract: A system and method for non-invasively tracking a particle in a sample is disclosed. The system includes a 2-photon or confocal laser scanning microscope (LSM) and a particle-holding device coupled to a stage with X-Y and Z position control. The system also includes a tracking module having a tracking excitation laser, X-Y and Z radiation-gathering components configured to detect deviations of the particle in an X-Y and Z directions. The system also includes a processor coupled to the X-Y and Z radiation gathering components, generate control signals configured to drive the stage X-Y and Z position controls to track the movement of the particle. The system may also include a synchronization module configured to generate LSM pixels stamped with stage position and a processing module configured to generate a 3D image showing the 3D trajectory of a particle using the LSM pixels stamped with stage position.

Abstract: A system and method for non-invasively tracking a particle in a sample is disclosed. The system includes a 2-photon or confocal laser scanning microscope (LSM) and a particle-holding device coupled to a stage with X-Y and Z position control. The system also includes a tracking module having a tracking excitation laser, X-Y and Z radiation-gathering components configured to detect deviations of the particle in an X-Y and Z directions. The system also includes a processor coupled to the X-Y and Z radiation gathering components, generate control signals configured to drive the stage X-Y and Z position controls to track the movement of the particle. The system may also include a synchronization module configured to generate LSM pixels stamped with stage position and a processing module configured to generate a 3D image showing the 3D trajectory of a particle using the LSM pixels stamped with stage position.

Abstract: Novel Mn2+-doped quantum dots are provided. These Mn2+-doped quantum dots exhibit excellent temperature sensitivity in both organic solvents and water-based solutions. Methods of preparing the Mn2+-doped quantum dots are provided. The Mn2+-doped quantum dots may be prepared via a stepwise procedure using air-stable and inexpensive chemicals. The use of air-stable chemicals can significantly reduce the cost of synthesis, chemical storage, and the risk associated with handling flammable chemicals. Methods of temperature sensing using Mn2+-doped quantum dots are provided. The stepwise procedure provides the ability to tune the temperature-sensing properties to satisfy specific needs for temperature sensing applications. Water solubility may be achieved by passivating the Mn2+-doped quantum dots, allowing the Mn2+-doped quantum dots to probe the fluctuations of local temperature in biological environments.

Abstract: A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

Abstract: A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.