Biosensors could transform rapid monitoring of multiple waterborne pathogens

Waterborne pathogens remain a major threat to public health, but many current monitoring methods are too slow or too narrowly focused to provide rapid warning of emerging biological risks. A new perspective published in Biocontaminant outlines how integrated biosensing systems could move aquatic pathogen surveillance from periodic single-target testing toward rapid, online monitoring of multiple pathogens at once.

"The key challenge is no longer simply detecting pathogens with greater sensitivity, but increasing monitoring frequency and expanding surveillance from individual targets to multiple priority pathogens in near real time," the authors said.

Traditional culture methods remain valuable for determining whether microorganisms are viable, while PCR and sequencing provide sensitive detection and detailed characterization. However, these approaches commonly depend on sample collection, laboratory processing, specialized instruments, and subsequent analysis, which limits their use for continuous in situ monitoring.

The authors highlight several emerging technologies that could help bridge this gap. Nanobody-based recognition combined with fiberoptic sensors may enable rapid first-line screening of several predefined pathogens, while functional nucleic acid probes, including aptamers and deoxyribozymes, could provide more specific secondary analysis. Microfluidic platforms could further automate sample handling and parallel detection.

The proposed framework, illustrated in the paper, combines automated sampling, pathogen concentration, multiplex recognition, rapid signal detection, data analysis, and early warning. Culture, PCR, or sequencing would remain available for confirmation and deeper characterization when necessary.

The authors also stress that practical deployment will require more than highly sensitive sensors. Low pathogen concentrations, complex water matrices, biofouling, sensor drift, cross-reactivity, calibration, and long-term operational stability remain important obstacles.

Rather than replacing established laboratory methods, the authors envision biosensors as complementary tools that could shorten response times and strengthen early warning systems. Integrating these technologies into reliable multipathogen surveillance networks may improve aquatic biosafety and support faster management of waterborne biological risks.