A Home-Built Magnetic Particle-Based Automated System for Viral Detection in Large-Volume Wastewater

Enriching trace viruses in large-volume wastewater samples
is essential
to ensure the detection accuracy of wastewater-based epidemiology,
yet it is limited by laborious operations and low recovery efficiency.
Magnetic particle (MP)-based approaches have the potential for automating
enrichment processing and are considered a convenient alternative.
However, automated applications for large-volume samples are hindered
by the lack of MPs with satisfactory properties. In this study, we
presented a novel large-volume viral enrichment system composed of
elaborately prepared MPs and an automated platform. Due to the high
magnetic responsiveness, excellent dispersibility, and selective absorption
performance of MPs, the system enabled the automatic processing of
up to 180 mL of large-volume samples without requiring centrifugation
or ultrafiltration. A 0.2 copies/mL experimental sensitivity was achieved
in spiked samples, which is 25-fold more sensitive than previous automated
studies. The practical applicability has been validated through testing
real wastewater samples, demonstrating a 4.5-fold detection accuracy
for SARS-CoV-2 monitoring compared with the traditional protocol.
Overall, the successful explorations on the designs of MPs address
the challenges for automatedly enriching large-volume samples and
endow the system with simplicity and efficiency, which offer a novel
alternative tool for large-scale epidemiological surveillance.