Aptamer-based biosensors have narrowed the gap between laboratory accuracy and rapid virus testing

DNA and RNA aptamers can power portable biosensors that detect viruses within minutes, with potential uses beyond clinical diagnostics in outbreak early warning and environmental monitoring

Rapid and reliable virus detection has remained central to outbreak control, from seasonal influenza to pandemics such as COVID-19. Major advances in aptamer-based biosensors, a class of diagnostic tools that researchers have developed to deliver faster, cheaper and more portable testing in clinics, communities and field settings.

The review, led by researchers at Dalian University of Technology, Liaoning, China, examined how scientists have engineered short strands of DNA or RNA called aptamers into biosensors for viral detection. Aptamers can bind viral targets with high precision – much like antibodies – but they are easier to manufacture, more stable at high temperatures and simpler to modify for different sensing platforms. These properties make aptamers particularly attractive for diagnostics outside traditional laboratories and in resource-limited settings.

“Reliable viral detection underpins nearly every public health response, from patient diagnosis to outbreak surveillance,” said corresponding author Dr. Jiuxing Li.

“Our review shows that aptamer-based biosensors are rapidly closing the gap between laboratory accuracy and real-world usability,” they added.

Cell cultures can confirm infection but can be slow and require specialised facilities. Rapid antigen tests are faster but can also lack sensitivity. And testing with polymerase chain reaction, the laboratory reference method, offers high accuracy but depends on costly instrumentation and highly trained personnel. These trade-offs can delay detection, especially where laboratory infrastructure is limited or in high demand.

Aptamer-based biosensors aim to overcome such limitations by combining synthetic recognition molecules with compact detection hardware. Aptamers are selected in vitro through systematic evolution of ligands by exponential enrichment (SELEX), a process that identifies sequences that bind tightly and specifically to a target such as a viral protein or intact virion. Unlike antibodies, aptamers are fully synthetic, allowing precise control over their structure, chemistry and cost.

The review described refinements to SELEX that have improved speed, efficiency and binding performance. Such advances have become crucial as viral mutations continue to challenge diagnostics, particularly when they alter epitopes that tests rely on. By selecting aptamers against conserved regions and by refining selection conditions to resemble real samples, the research aims to maintain diagnostic performance as viruses evolve.

Once selected, aptamers can form the recognition element in biosensors that convert binding events into measurable signals. The review covered electrochemical sensors that detect changes in current or voltage, fluorescence and colour-change assays readable by eye or smartphone, and optical platforms such as surface plasmon resonance and surface-enhanced Raman scattering for ultra-sensitive detection.

“These biosensors can be designed for rapid testing outside traditional laboratories. Some platforms can deliver results in minutes, require minimal sample preparation, and operate with portable or handheld devices,” said co-corresponding author Meng Liu.

The authors also emphasised that aptamer-based biosensors are not limited to clinical diagnostics. They show strong potential for environmental monitoring, food safety and early warning systems that can detect viruses on surfaces or in water and air before outbreaks escalate. Such applications could strengthen surveillance in hospitals, airports and food production sites, where rapid alerts can support targeted interventions.

Despite the progress, the authors noted that barriers remain before aptamer-based biosensors can achieve widespread deployment. Large-scale validation in clinical and environmental samples, standardisation of performance metrics and robust manufacturing processes are all necessary to ensure reliability. They also highlighted the importance of integrating assays into real-world workflows, from sample collection to data reporting, so that speed at the sensor translates into faster decision-making.

The review suggested that further gains could follow from combining aptamer technology with microfluidics, nanomaterials and data analysis tools. Microfluidic systems can automate sample handling and improve reproducibility. Nanomaterials can amplify signals and enhance sensitivity. Data processing algorithms can help to distinguish true positives from background noise and support digital result reporting for public health monitoring.

“Our goal is to provide a clear framework for researchers and developers. By understanding both the strengths and the remaining hurdles, we can accelerate the translation of these biosensors from the lab to practical use,” said Li.

As governments and health systems continue to prepare for future viral threats, aptamer-based biosensors could become an important component of the diagnostic toolkit. By pairing synthetic recognition molecules with portable readouts, these platforms may help to expand testing access, shorten the time from sample to result and support surveillance where early detection matters most.

For further reading please visit: 10.48130/biocontam-0025-0018