SBIR-STTR Award

Fluorescence based techniques play an essential role in modern cell biology and biomedical research. Further development of these techniques has been hindered by the lack of suitable fluorescent probes. To overcome this challenge, various fluorescent nanoparticles have been developed. Among those, conjugated polymer dots (Pdots) exhibited superior properties such as high brightness, fast emission rate, and excellent photostability. However, a severe drawback associated with Pdots is their broad emission spectra, which significantly limit their usefulness in practical applications. This proposal describes the refinement of a new class of Pdots that emit at different wavelengths with narrow spectral bandwidth. To achieve this goal, we propose the following aims: (1) Develop multicolor bright polymer dots with emission bandwidth FWHM that is comparable to or less than 40 nm. Here, we will carry out various spectroscopic techniques to characterize the Pdot properties such as absorption cross section, emission bandwidth, fluorescence quantum yield, photostability, and fluorescence lifetime. Single-particle fluorescence imaging will also be performed to provide side-by-side brightness comparisons on Pdots versus inorganic quantum dots (Qdots) (2) Optimize nanoparticle surface properties to reduce nonspecific labeling. Here, to examine nonspecific labeling of Pdots, we will use a range of techniques, including gel electrophoresis, dynamic laser scattering, affinity chromatography, flow cytometry, and fluorescence spectroscopy/imaging. (3) Demonstrate multiplex detection of biomolecules in cellular environments. Here, we will use the bright, narrow-band Pdots for multiplex detection of biomolecules in cellular environments. Specifically, flow cytometry and fluorescence imaging will be performed to evaluate the labeling specificity and compare fluorescence brightness of the labeled targets. Reliable protocols will be established for simultaneous labeling of three or more cellular targets with multicolor Pdots. This will lay the foundation of applying these bright, narrow-band Pdots for multiplex detection and biological imaging.

Thesaurus Terms:
Absorption;Affinity Chromatography;Antibodies;Antibody Conjugate;Base;Binding (Molecular Function);Biological;Biological Assay;Biomedical Research;Cell Surface Receptors;Cellular Biology;Cellular Targeting;Chemical Group;Clinical;Color;Complex;Cytoskeleton;Detection;Development;Development Plans;Diagnostic;Dyes;Environment;Exhibits;Flow Cytometry;Fluorescence;Fluorescence Imaging;Fluorescence Spectroscopy;Fluorescent Antibody Technique;Fluorescent Dyes;Fluorescent Probes;Foundations;Functional Group;Gel Electrophoresis;Goals;Image;Imaging Techniques;Label;Lasers;Multiplex Detection;Nanoparticle;Nuclear Receptors;Oranges;Particle;Particle Size;Performance;Play;Polymers;Practical Application;Principal Investigator;Procedures;Property;Proteins;Protocols Documentation;Public Health Relevance;Quantum;Quantum Dots;Role;Side;Specificity;Streptavidin;Structure;Surface Properties;Technique Development;Techniques;Technology;

Fluorescence based methods play an essential role in modern cell biology and biomedical research. Further development of these techniques has been hindered by the lack of suitable fluorescent probes. To overcome this challenge, various fluorescent nanoparticles have been developed. Among those, semiconducting polymer dots (Pdots) exhibit superior properties such as high brightness, fast emission rate, and excellent photo stability. Fluorescence based techniques encompass a broad area with a large market size, ranging from immuno-assays to super-resolution imaging. And while Pdot has proven to be an excellent general fluorescent probe, to maintain focus, to penetrate the market, and to generate adoption by the biomedical community, we have decided to go after flow cytometry applications, owing to its large market potential. During our 6-month Phase I SBIR project, we have developed Pdot450 and Pdot515 with ultra- high brightness, narrow-band emission, and high photo stability. To achieve this goal of penetrating the flow cytometry market, this Phase II SBIR project proposes to develop 5 additional Pdot probes to complement the 2 developed during Phase I. After this Phase II project, we will have completed a set of 7 Pdots so we may launch a Pdot series with high brightness and narrow emissions for flow cytometry applications. Furthermore, we will establish pre-production and quality control protocols for manufacturing this Pdot series.

Public Health Relevance Statement:


Public Health Relevance:
Fluorescence based techniques play an essential role in modern cell biology and biomedical research as well as in various clinical diagnostic assays. This proposal aims to develop a new class of fluorescent probes that should offer significant performance improvements over traditional fluorescent dyes and nanoparticles. When successfully developed, this new probe will find broad use in biomedical research and clinical diagnostics.

NIH Spending Category:
Bioengineering; Nanotechnology

Project Terms:
Adoption; Antigens; Area; base; Benchmarking; Biological Assay; Biological Sciences; Biomedical Research; Caliber; Cellular biology; Clinical; Communities; community science; Complement 2; density; design; Detection; Development; Diagnostic; diagnostic assay; Dyes; Exhibits; Financial compensation; Flow Cytometry; Fluorescence; Fluorescent Dyes; Fluorescent Probes; fluorophore; functional group; genetic analysis; Goals; Image; Lasers; manufacturing process; Marketing; Methods; nanoparticle; optical spectra; particle; Performance; Phase; Phycoerythrin; Play; Polymers; Production; Property; Protocols documentation; public health relevance; Quality Control; Reagent; Reproducibility; Resolution; Role; Series; Small Business Innovation Research Grant; success; Surface; technique development; Techniques; Time; Translating; Viola; Width; Work; zeta potential