SBIR Phase I: Development of Cadmium-Free, Water-Soluble and Multicolor Quantum Dots by Chemical Doping

这个小企业创新研究一期项目将通过化学掺杂的方式合成无镉、水溶性、多色的量子点，作为生物和生物医学领域的荧光体。随着量子点标记的普及，目前广泛使用的基于镉的量子点的固有毒性引起了人们的关注。易于调节不同的发射颜色一直是基于镉的量子点的一大优势。然而，对于生物医学应用，不同尺寸的量子点可能会影响它们在细胞和组织中的迁移率，从而可能降低多分析研究中的诊断准确性和灵敏度。这项NSF SBIR第一阶段计划将通过化学掺杂合成无镉、水溶性和多色量子点(QD)。首先合成掺杂的核/壳量子点，然后通过生物医学应用的专利方法将其转化为水溶性和生物相容性的量子点。在第一阶段，该项目将开发合成建议的量子点的技术，第二阶段将扩大合成规模，用于大规模生产。在商业上，量子点被认为是一类新的荧光探针，具有广泛的应用，包括单分子生物物理、生物分子轮廓、光学条形码和活体成像。与有机染料和荧光蛋白相比，量子点具有独特的光学和电学性质，包括尺寸可调的发光、改善的信号亮度、抗光漂白和同时激发多种荧光颜色。尽管生物技术和学术界对生物兼容纳米晶体的需求迅速增长，但到目前为止，只有两家公司在市场上推出了商业产品。然而，他们所有的产品都是基于镉的，而且极其昂贵。所提出的技术的成功开发将导致新一代生物标记的产生，并在量子点的生物医学应用方面取得重大进展。

This Small Business Innovation Research Phase I project will synthesize cadmium-free, water-soluble, and multicolor quantum dots (QDs) by chemical doping, which can be used as fluorophores in the fields of biology and biomedicine. As the popularity of QD labeling soars, concerns are raised on the inherent toxicity ofcurrent widely used cadmium-based QDs. The easiness in tuning different emission colors has been a big advantage of cadmium-based QDs. However, for biomedical applications, the different particle sizes of QDs could influence their mobility in cells and tissues, and thus may reduce the diagnostic accuracy and sensitivity in multianalyte studies. This NSF SBIR Phase I program will synthesize cadmium free,water-soluble, and multicolor quantum dots (QDs) by chemical doping. The doped core/shell QDs will be synthesized first and then converted to water-soluble and biocompatible through proprietary methods for biomedical applications. In Phase I, this project will develop the techniques for the synthesis of proposed QDs and Phase II will scale up the synthesis for massive production.Commercially, QDs are considered as a new class of fluorescent probes with a broad range of applications including single molecule biophysics, biomolecular profiling, optical barcoding, and in vivo imaging. In comparison with organic dyes and fluorescent proteins, QDs have unique optical and electronic properties including size-tunable light emission, improved signal brightness, resistance against photobleaching, andsimultaneous excitation of multiple fluorescence colors. Despite the fast growing need for biocompatible nanocrystals by biotech as well as academia, to date, only two other companies have launched commercial products in the markets. However, all their products are cadmium based and extremely expensive. Successful development of proposed techniques will result in a new generation of biolabels and make significantadvances in the biomedical applications of QDs.