From melanoma to malaria: photoacoustic device detects disease without taking a single drop of blood
Source: Physics World, November 2024
Malaria remains a serious health concern, with annual deaths increasing yearly since 2019 and almost half of the world’s population at risk of infection. Existing diagnostic tests are less than optimal and all rely on obtaining an invasive blood sample. Now, a research collaboration from USA and Cameroon has demonstrated a device that can non-invasively detect this potentially deadly infection without requiring a single drop of blood.
Currently, malaria is diagnosed using optical microscopy or antigen-based rapid diagnostic tests, but both methods have low sensitivity. Polymerase chain reaction (PCR) tests are more sensitive, but still require blood sampling. The new platform – Cytophone – uses photoacoustic flow cytometry (PAFC) to rapidly identify malaria-infected red blood cells via a small probe placed on the back of the hand.
PAFC works by delivering low-energy laser pulses through the skin into a blood vessel and recording the thermoacoustic signals generated by absorbers in circulating blood. Cytophone, invented by Vladimir Zharov from the University of Arkansas for Medical Science, was originally developed as a universal diagnostic platform and first tested clinically for detection of cancerous melanoma cells.