African Laser Centre pairs Cairo’s signal-booster nanoparticles with Pretoria’s biophotonics
In 2026, the CSIR and Cairo University began developing an innovative laser-based sensor designed to quickly, affordably and efficiently detect and quantify human immunodeficiency virus (HIV), without the need for prolonged and expensive laboratory processes.
The project builds on pan-African laser and photonics science supported by the CSIR’s African Laser Centre (ALC) for more than 20 years: experienced researchers in the CSIR biophotonics research group and Cairo University's National Institute of Laser Enhanced Science are confident they can develop an optical biosensor to detect the precise chemical fingerprint of viral targets.
CSIR biophotonics researcher Dr Lungile Thwala says the CSIR is home to a specialised, state-of-the-art Raman microscope that can detect and quantify just about any material, including biological samples. Raman spectroscopy works by shining a laser onto a sample and measuring the tiny shift in the wavelength of light that scatters back (known as the Raman shift), producing a tell-tale signature for each molecule.
"No two molecules have the same Raman fingerprint, so it is ultrasensitive and it is faster than, for example, current PCR methods,” says Thwala. PCR stands for polymerase chain reaction, a laboratory method used to amplify genetic material from viruses or other infectious agents for diagnostic purposes.
Dr Lungile Thwala uses the CSIR’s new Raman microscope in the biophotonics laboratory (left). She shows how data from the microscope reveals each molecule’s unique fingerprint spectrum.
Key to the research project is identifying the best metallic nanoparticle to bind to the target viral particle before measuring with a Raman microscope: nanoparticles act as signal-boosters since they create intense local electromagnetic fields when hit by a laser, thus amplifying the Raman signal.
“For this project, we are strengthening our existing collaboration with our Egyptian partner, Prof. Ahmed El-Hussein. His group has expertise in software modelling and synthesis of metallic nanoparticles that can improve the sensitivity of optics-based biosensors,” says Thwala.
The research team will thus use software modelling to identify the most suitable metal nanoparticles to act as a substrate for the target HIV particles in patient samples.
Dr Sello Manoto, who leads the CSIR biophotonics research group, says that once the process of detecting and quantifying HIV in this brand-new way has been validated with the benchtop Raman microscope, they will build a bespoke and portable Raman system. “The future plan is to develop a point-of-care device that can be deployed in resource-limited settings across Africa,” he says.
He says that while research partners outside the continent often have blind spots when it comes to such useful innovations for Africa, partners within understand local contexts and constraints.
“It is beneficial because we are able to solve common challenges that we face as the African continent.”
Dr Masixole Lugongolo, also a CSIR biophotonics expert, says this is why the ALC is such a great platform. “We get to interact with and explore the skills of other researchers on the continent and it opens opportunities for research exchanges, visits and even supervising non-South African students.”
The ALC has been expanding the continent’s laser and photonics research footprint since it was established in 2003 as a flagship African Union development programme. Backed by South Africa’s Department of Science, Technology and Innovation, it operates as a virtual, open network of African photonics, laser and optics research nodes. The goal is to build skills and researcher collaborations, expand access to facilities and equipment, reduce brain drain and support innovations that can translate into real-world solutions.
The number of peer-reviewed scientific publications resulting from this support now stands at nearly 800 and in the past decade alone, over 100 Master's and Doctoral students were funded.
“We now have a very strong photonics-focused programme across Africa that addresses many different sectors in our economies,” says the CSIR’s Hardus Greyling, who is responsible for coordinating the ALC’s funding programmes.
He says the centre’s focus is not just on blue-sky research or research for the sake of research. “All projects we support must submit plans for commercialisation and getting the product into market, whether it is for medical, industrial or communication applications.”
Greyling says a good example of how the ALC helps build lasting research capacity is a partnership between South Africa’s Prof. Mark Tame, at Stellenbosch University and Dr Amos Kiyumbi from the University of Dar es Salaam in Tanzania. What began as a scholarship-supported link has blossomed into a full-scale research collaboration on malaria biosensors.
“We had awarded Kiyumbi a scholarship and he is now completed his doctorate and is establishing his own research group in Tanzania. So, this is the good fruit that comes from the ALC: you set up the opportunity for people to establish new research capabilities and to set up their own research competency in their country through mechanisms such as the ALC Scholarship Programme or the ALC Knowledge Transfer Programme.”
Every year, the centre supports between 15 and 20 laser research projects across the continent, typically awarding between R125 000 and R180 000 per project.
In 2018, during a research project funded by the ALC, the CSIR’s biophotonics team first established a connection with Cairo University's nanoparticle expert El-Hussein.
They wanted to see if they could modify a smartphone camera with a special grating to act as a spectrometer for HIV detection. The idea was to capture the light spectrum after it passes through the sample consisting of HIV-specific antibodies bound to the target viral particles on a treated glass slide and to boost the signal using nanoparticles.
The team also built in-house software and added machine learning to classify samples as positive or negative and to estimate viral load, aiming to reduce human error and speed up analysis.
But scaling-up and commercialising such biosensor technologies requires significant funding and time, as well as regulatory approval.
Greyling, Lugongolo, Manoto and Thwala agree that biophotonics technologies like HIV biosensors will only be adopted in clinical settings if society works with scientists. They encourage venture capitalists, pathology laboratories, small businesses, health authorities and historically disadvantaged institutions to partner with established research institutions like the CSIR and others on the continent to help bring these products to market.
“Our new laser-based diagnostic approach will allow for early and rapid detection of infectious diseases such as HIV, which implies that interventions or treatments can be initiated sooner and hence improve lives,” says Thwala.
Published 25 May 2026