Our goal is to develop easy to use, inexpensive, and sensitive quantum dots beads (QDBs) based strip test for multiplex diagnosis of human malaria infection called MAL-QDBTest" that can detect as low as 1 parasite/uL in a <20 min assay. The MAL-QDBTest" consists of 1) multiplexed strip test for qualitative visual detection (Fig. 1), 2) reagents for the strip test, and 3) an optional a handheld fluorescence reader called QD-Analyzer". The MAL-QDBTest" uses novel quantum dots beads in a multiplex strip test that is used both for a) qualitative detection using visual inspection and b) quantitative detection using the QD- Analyzer". The MAL-QDTest" uses novel quantum dots beads (QDBs) that can be used to differentiate a) Pfalciparum from Pvivax;b) detect other Plasmodia causing malaria;c) differentiate live from dead parasites through the detection of pGluDH;and d) quantify the number of parasites present with the use of the QD- Analyzer. It uses quantum dots beads (QDBs) which are nanoparticles (NPs) containing hundreds of quantum dots that exhibit color stability and high light intensity greater than organic dyes. Quantum confined properties of quantum dots with a few atoms to 10,000 atoms can enable single molecule detection. Interfaced with the QD-Analyzer, the QDB-based multiplex detection will provide higher sensitivity, greater reproducibility, lower detection limits, and increased diagnostic accuracy. The proposed multiplex MAL-QDBTest" uses patented QDBs that can be conjugated to selective and specific antibodies for the capture and detection of antigen biomarkers of malaria infection. To date, there is no existing malaria assay that uses QDBs which are sacs of hundreds of NPs that exhibit color stability and high light intensity that are 100% greater than organic dyes with the potential to detect a single molecule. There is a great need for developing better detection methods for malaria parasites because not only does current diagnosis suffer from sensitivity and reliability of results, these cannot detect lower than 100 parasites /uL may be fatal. The sensitivity of current rapid diagnostic tests may be >85% but only at 200 parasites/uL or higher. These cannot be used for drug/vaccine development that requires 1 parasite/uL detection. The proposed MAL-QDBTest" is anticipated to alleviate the diagnosis of >500 million cases of malaria each year with 1-3 million deaths and the drug and vaccine development hurdles. Currently, there is no no licensed vaccine against this disease. In the US, malaria may re-emerge due to increased travel to endemic countries as well as the deployment of the >300,000 US military personnel worldwide. Furthermore, the number of blood donors who had been refused as a result of recent travel to endemic countries has been >10% that may have caused shortage at blood banks around the country. Thus, there is a need to develop the proposed MAL-QDBTest" interfaced with the QD-Analyzer for fast, easy to use, reliable, quantitative, and inexpensive methods for malaria diagnosis and to quickly validate drug and vaccine candidates.

Public Health Relevance

The proposed quantum dots based strip test for multiplex diagnosis of human malaria infection is anticipated to alleviate the diagnostics as well as the drug and vaccine hurdles that affect >500 million cases of malaria each year and 1 to 3 million deaths, majority of whom are young children. Although there are recent advances in medicine, science, and technology, there is no licensed vaccine against this disease that is a major infectious disease threat to U.S. forces deployed worldwide. In the US, malaria is recently considered to have a high potential to re-emerge due to the spread of drug resistant parasites and insecticide-resistant mosquitoes and as a result the number of blood donors who had been refused as a result of recent travel to endemic countries has been more than 10% possibly causing shortage at blood banks around the country.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Small Business Innovation Research Grants (SBIR) - Phase I (R43)
Project #
5R43AI092962-02
Application #
8302222
Study Section
Special Emphasis Panel (ZRG1-IDM-P (12))
Program Officer
Rao, Malla R
Project Start
2011-08-01
Project End
2013-07-31
Budget Start
2012-08-01
Budget End
2013-07-31
Support Year
2
Fiscal Year
2012
Total Cost
$294,664
Indirect Cost
Name
Ocean Nanotech, LLC
Department
Type
DUNS #
155516987
City
Springdale
State
AR
Country
United States
Zip Code
72764
Ren, Meiling; Xu, Hengyi; Huang, Xiaolin et al. (2014) Immunochromatographic assay for ultrasensitive detection of aflatoxin B? in maize by highly luminescent quantum dot beads. ACS Appl Mater Interfaces 6:14215-22