Label-free HIV-1 Viral Load Measurement through a Contactless Electrode Microchip

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DESCRIPTION: Rapid, inexpensive, and early detection of infectious viral diseases is an urgent unmet need with diverse applications ranging from clinical diagnosis, public health, and homeland security. Among these applications, Human Immunodeficiency Virus (HIV-1) diagnostics in resource-limited settings plays a critical role to provide appropriate and timely care to patients. More than 95% of deaths due to infectious diseases such as malaria, Acquired Immune Deficiency Syndrome (AIDS), and tuberculosis (TB) have been reported to occur in developing countries. A significant ratio (67%) of the 33.3 million HIV-1 infected population live in Sub-Saharan Africa. These statistics clearly highlight the urgent demand for rapid, inexpensive, and simple screening tests to identify infected individuals for HIV/AIDS treatment. However, current HIV-1 diagnostics such as lateral flow assays, including dipsticks or enzyme immunoassays (ELISA), and OraQuick HIV test kit lack the capability to detect acute HIV-1 infection even at high HIV-1 viral load. Detecting persons with acute HIV-1 infection is crucial since viral replication and shedding occur in this stage before detectable HIV-1 antibodies appear. Persons with acute HIV-1 infection are unaware of their disease and therefore contribute substantially to HIV-1 transmission. At this stage, there is maximum viral replication and shedding (108 copies/mL). Thus, there is an immediate need for easy to use, portable, and inexpensive diagnostic tool for acute HIV-1 detection (seroconversion and asymptomatic stages) at the POC. At the Bio-Acoustic MEMS in Medicine laboratory at Harvard Medical School, Dr. Demirci's (Sponsor) team has presented prototype viral load counting platforms based on lensless and fluorescence imaging. Here, I will employ my previous expertise in microfluidic cell electro-manipulation and my current expertise in antibody based HIV-1 virus capturing using micro/nano technologies to create a POC HIV-1 viral load measurement platform for treatment initiation and monitoring. Streptavidin-coated nano-magnetic beads conjugated with gp120 antibody will be used to selectively capture and isolate HIV-1 viruses from whole blood samples. The nanobead-HIV virus complexes will be then introduced into the microfluidic device with the optimized contactless microelectrodes functionalized with gp120 antibody to capture the nanobead-HIV complex. The captured viruses will be lysed through introducing a lysis detergent and the impedance change will be correlated to the viral load of the sample. This proposal will provide an inexpensive method for HIV-1 viral load measurements at POC that is compatible with mass fabrication technologies with a great promise to be commercialized.