Towards an ultra-rapid smartphone- connected test for infectious diseases

Abstract

The development is reported of an ultra-rapid, point-of-care diagnostic device which harnesses surface acoustic wave (SAW) biochips, to detect HIV in a finger prick of blood within 10 seconds (samplein-result-out). The disposable quartz biochip, based on microelectronic components found in every consumer smartphone, is extremely fast because no complex labelling, amplification or wash steps are needed. A pocket-sized control box reads out the SAW signal and displays results electronically. High analytical sensitivity and specificity are found with model and real patient blood samples. The findings presented here open up the potential of consumer electronics to cut lengthy test waiting times, giving patients on the spot access to potentially life-saving treatment and supporting more timely public health interventions to prevent disease transmission.Ebola and Zika viruses offer a stark reminder that infectious diseases rank among the gravest threats to human health, and can spread rapidly and unpredictably. New infections will continue to emerge each year, and old enemies re-emerge, increasingly with acquired-drug resistance (e.g. gonorrhoea and HIV). Rapid diagnosis plays a crucial role in any outbreak situation, empowering patients to gain faster access to potentially life-saving treatment, and informing prevention strategies to protect the wider public. However, routine diagnostic tests based on enzyme linked immunosorbent assays (ELISAs) and polymerase chain reaction (PCR) are confined to centralized laboratories often requiring large, sophisticated, costly instrumentation and highly trained staff. Inherent delays occur between taking samples, conveying them to the laboratory, waiting for results to come back and subsequent follow up appointments 1-3 . This means that a patient often has to make multiple visits to a clinic in order to receive treatment, potentially over long distances. This delays prescribing of treatment with increased risk of suffering, mortality, and also incorrect prescription of antimicrobials.Recent policy drivers aim to widen access to testing using so called 'rapid' point-of-care tests (POCT) but the performance and implementation of these tests still remain a challenge 4 . The most common tests based on lateral flow technology are still relatively slow, requiring a 10-20 minute waiting time for results 5 . This exceeds a typical doctor's appointment (8-10 mins in the UK 6 ) necessitating changes to patient pathways within a clinic with additional on-costs and staffing implications. It is also notoriously difficult to interpret a faint lateral flow test line by eye, particularly for non-experts (e.g. self-testers) 1 . Those tests that are currently available are insensitive to recent (acute) infections 7 and lack the ability to automatically capture test results electronically, risking an incorrect reading, missed opportunities to link patients to care pathways and potential data loss for public health (e.g. during an Ebola outbreak) 8 . Alternatively, uneccesary treatment may be initi...

A review of smartphone point‐of‐care adapter design

“…Biological objects such as bacteria, viruses, and parasites are in the micrometer to submicrometer range; therefore, magnification is mandatory for visual inspection of these objects. Smartphone adapters are employed here for visual inspection, measurement, recognition, sensing, and disease diagnosis for conditions such as diabetes, cancer, and malaria . On the other hand, chemical agents, such as hormones, biomarkers, and reagents, are essential for biochemical processes; therefore, smartphone adapters were neatly designed for sensing, measuring, and monitoring these agents, as shown in Figure .…”

An aptamer-based shear horizontal surface acoustic wave biosensor with a CVD-grown single-layered graphene film for high-sensitivity detection of a label-free endotoxin

“…Shear horizontal surface acoustic wave (SH-SAW) biosensors have been widely reported owing to aspects such as their high selectivity and/or sensitive detection of deoxyribonucleic acid (DNA), 18 proteins, 19 and cells. [20][21][22][23] SH-SAW biosensors have the advantages of low cost, operational simplicity, and high sensitivity, and these biosensors can be used in label-free and real-time monitoring. Additionally, SH-SAW biosensors are especially suitable for biological detection in a liquid phase, as the particle displacement is parallel to the SAW propagation direction.…”

From Point-of-Care Testing to eHealth Diagnostic Devices (eDiagnostics)

“…(A) Paper strip for urinalysis; (B) paper-based device for accessing liver function; (C) cellphone attachment that reads disposable lateral flow tests; (D) sample in–result out device for analyzing nasal swab to detect nucleic acids; (E) microfluidic cassette connected to a smartphone dongle for infectious diseases detection; (F) SAW (surface acoustic waves) biochip for the HIV detection in blood; (G) chip-based microfluidic device for the detection of lithium in blood; (H) wristband for real-time detection of glucose, sodium, and chloride ions in sweat; (I) sweat-monitoring patch for measuring sweat rate, temperature, and chloride ions concentration; and (J) mouthguard that integrates a biosensor and a wireless circuit board for uric acid detection in saliva. The figures were reproduced with permission from refs (93) (A), (201) (B), (112) (C), (137) (D), (199) (E), (192) (F), (195) (G), (45) (H), (59) (I), and (72) (J).…”