Wastewater analysis of pathogens, particularly SARS-CoV-2,
is instrumental
in tracking and monitoring infectious diseases in a population. This
method can be used to generate early warnings regarding the onset
of an infectious disease and predict the associated infection trends.
Currently, wastewater analysis of SARS-CoV-2 is almost exclusively
performed using polymerase chain reaction for the amplification-based
detection of viral RNA at centralized laboratories. Despite the development
of several biosensing technologies offering point-of-care solutions
for analyzing SARS-CoV-2 in clinical samples, these remain elusive
for wastewater analysis due to the low levels of the virus and the
interference caused by the wastewater matrix. Herein, we integrate
an aptamer-based electrochemical chip with a filtration, purification,
and extraction (FPE) system for developing an alternate in-field solution
for wastewater analysis. The sensing chip employs a dimeric aptamer,
which is universally applicable to the wild-type, alpha, delta, and
omicron variants of SARS-CoV-2. We demonstrate that the aptamer is
stable in the wastewater matrix (diluted to 50%) and its binding affinity
is not significantly impacted. The sensing chip demonstrates a limit
of detection of 1000 copies/L (1 copy/mL), enabled by the amplification
provided by the FPE system. This allows the integrated system to detect
trace amounts of the virus in native wastewater and categorize the
amount of contamination into trace (<10 copies/mL), medium (10–1000
copies/mL), or high (>1000 copies/mL) levels, providing a viable
wastewater
analysis solution for in-field use.