This SBIR Phase II program aims to develop a novel class of commercial products of near infrared (NIR) nanolabels based on colloidal non-cadmium quantum dots, InAs/InP/ZnSe core/shell/shell dots coated with dendron ligands. NIR emitters are outstanding bio-medical labels because of the close-to-zero background of biological tissues in the NIR window. The traditional organic dyes are very inefficient (single digit in percentage of quantum yield) and unstable. Most NIR bio-medical labels based on quantum dots reported in literature today are based on cadmium, mercury, or lead elements, which are extremely toxic and unlikely to make into the real life applications because of the tightened environmental policies. InAs based core/shell nanocrystals are considered as the most promising NIR nanolabels if the shell materials don't contain Cd, Hg and Pb elements involved. Unlike zero tolerance of Cd, Hg and Pb in today's regulation environment in advanced countries, human body can tolerate a small amount of indium, arsenic and selenium. During the Phase I program, this SBIR team finally overcame the main scientific hurdles for realizing such a promising system, i.e., InAs/InP/ZnSe core/shell/shell dots, as NIR nanolabels. The system demonstrated by us is not only non- cadmium in nature, but also of high brightness (~50% quantum yield), small in hydrodynamic sizes (<10 nm), stable in tested physiological conditions (such as full serum), and no appreciable specific bonding. The Phase II program shall develop these outstanding nanolabels for the market of general bio-medical labeling. In the following Phase III, this SBIR team shall further develop these unique NIR labels to several specific medical fields.
The success of this project will result in great benefits to the society and communities as follows: The ultra-sensitivity based on zero background NIR detection can in vivo diagnose and monitor cancer or other diseases in early stage, even to the resolution of single cell level. The simultaneous reading capability of multiple labels makes them be capable of addressing the biological and evolutionary diversity of the multiple cancer cells that make up a tumor within an individual. The commercialization of the proposed technologies will improve the health conditions of Americans, save lives, and help to maintain a sustainable environment.
