Human factors-designed triple test for HIV, HBV, and HCV infection in whole blood using target amplification, signal amplification, and crumpled graphene biosensor readout

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Abstract Access to frequent, accurate, and highly sensitive HIV viral load monitoring is a critical component of early infection diagnosis, HIV antiretroviral therapy, and routine diagnostic testing to keep people informed and help them maintain their HIV viral load status. The prevalence of co-infection with other viruses that present with similar symptoms, such as Hepatitis B virus (HBV) and Hepatitis C virus (HCV), drives the clinical need for multiplexed testing from the same blood sample. Although extensive research and product development has been applied to point-of-care (POC) viral load testing, the current paradigm of nucleic acid tests and antigen assays is inherently complex, lacks robustness, and is costly, which prohibits adoption in settings that serve key populations seeking care in lower stigma locations (e.g., community health centers vs. hospital settings). We seek to address this societal need, and technological gap, by advancing testing methods through the development of a microfluidic cartridge, molecular biology method, biosensor, and detection instrument that will simultaneously detect HIV, HBV, and HCV viral loads. This POC test will require minimal whole blood volume (100 L), take <30 minutes for sample-to-answer, and have superior sensitivity to PCR. Our nucleic acid test performs sample pre-processing in a microfluidic cartridge followed by virus-specific activation of CRISPR/Cas enzyme that rapidly releases large numbers of gold nanoparticle reporters that are subsequently captured and detected on crumpled graphene impedance-based biosensors. Our handheld, inexpensive (<$50) POC platform communicates its measurements to a mobile device (smartphone or tablet) to process current/voltage measurements from a custom circuit board. The affordable estimated cost per test (~$5) is based on our experience using the Additive Manufacturing approach for cartridge fabrication, combined with the low microfabrication cost of resistive sensors on silicon. Our preliminary data demonstrate the effectiveness of nucleic acid extraction from whole blood, the sensitivity/selectivity of the assay approach, and the sensitivity of the biosensors. The system will be evaluated using a rigorous tiered approach by spiking target nucleic acid sequences and viruses into buffer and whole blood for initial characterization of detection limits. We will validate the POC platform’s ability to detect HIV, HBV, and HCV in whole blood using clinical samples provided by our hospital collaborators in Illinois. Throughout the development and testing of the POC test, we will conduct rigorous human factor engineering and acceptability research with our behavioral scientist collaborators, who will mediate this iterative process to reflect the needs of clinicians, scientists, healthcare workers, health technicians, and potential end users represented by a scientific advisory group. The resulting platform will make a significant impact upon public health to those who lack easy access to sensitive, inexpensive, and triple rapid viral testing outside of traditional clinical settings.