May 30, 2021
Novel and robust point-of-care (POC) biosensors were designed and developed for the detection of two inherited blood disorders; glucose-6-phosphate dehydrogenase (G6PD) and phenylketonuria (PKU), with PreQuine Systems, Fig. 1a. The G6PD enzyme performs a critical function in human biochemistry. G6PD deficiency is among the most common enzyme pathology that affects 400 million people worldwide and is mainly found in malaria-endemic regions. Malaria affects over 200 million people yearly with 440,000 deaths. Malaria caused by Plasmodium vivax and by Plasmodium oval threatens over 2 billion people globally and sickens tens of millions annually. While treatments such as primaquine and tafenoquine provide a cure, over 8% of the global population are contraindicated due to inherited G6PD deficiency, as these treatments can cause serious, and often life-threatening, anemia. Therefore, a robust, user-friendly, and reliable test is necessary for diagnosing the G6PD deficiency to prevent hemolytic disorders while treating malaria. PreQuine is a novel platform for simultaneous quantification of G6PD and hemoglobin (Hgb) concentrations.
PKU is a genetic disorder that causes a build-up of amino acid, specifically L-phenylalanine (Phe), in the blood. PKU is the most common amino acid metabolic disorder and occurs in 1 out of every 8,000 newborns globally. Currently, whole blood is collected in EDTA tubes or spotted onto Dried Blood Spot (DBS) Cards by parents, patients, or caregivers. These samples are sent to laboratories for measurement by tandem mass spectrometry, and results can take days to weeks. This complicated process for monitoring and controlling Phe levels results in non-compliance, a decrease in quality of life, as well as increased healthcare costs for treating complications. Once diagnosed with PKU, Phe concentration levels must be monitored and maintained within acceptable limits between 2 – 6 mg/dL. If left untreated, infants can develop intellectual disabilities or suffer from other common side effects such as seizures, delayed development, behavioral problems, and psychiatric disorders. We have developed a vertical flow colorimetric assay for the quantitative determination of Phe in biological specimens. The assay requires only 15 µL of blood, the Phe within the specimen reacts with the reagent layer to produce an end-point color. This POC platform can be used at home, in the hospital, or at a clinician’s office to measure Phe concentrations and diagnose a patient with PKU.