Microfluidic device for concentration and SERS‐based detection of bacteria in drinking water

Abstract

There is a constant need for the development of easy-to-operate systems for the rapid and unambiguous identification of bacterial pathogens in drinking water without the requirement for time-consuming culture processes. In this study, we present a disposable and lowcost lab-on-a-chip device utilizing a nanoporous membrane, which connects two stacked perpendicular microfluidic channels. Whereas one of the channels supplies the sample, the second one attracts it by potential-driven forces. Surface-enhanced Raman spectrometry (SERS) is employed as a reliable detection method for bacteria identification. To gain the effect of surface enhancement, silver nanoparticles were added to the sample. The pores of the membrane act as a filter trapping the bodies of microorganisms as well as clusters of nanoparticles creating suitable conditions for sensitive SERS detection. Therein, we focused on the construction and characterization of the device performance. To demonstrate the functionality of the microfluidic chip, we analyzed common pathogens (Escherichia coli DH5α and Pseudomonas taiwanensis VLB120) from spiked tap water using the optimized experimental parameters. The obtained results confirmed our system to be promising for the construction of a disposable optical platform for reliable and rapid pathogen detection which couples their electrokinetic concentration on the integrated nanoporous membrane with SERS detection.

Recent advancements in microfluidic chip biosensor detection of foodborne pathogenic bacteria: a review

“…( a ) Side view, ( b ) cross-section, ( c ) the overall appearance of the LOC device for the concentration of bacteria followed by SERS detection. Reproduced from [ 118 ] with permission of John Wiley and Sons …”

“…In the past few decades, centrifugal microfluidic technology has made great progress, showing the rapid and automatic implementation of complex analysis. Krafft et al [ 118 ] developed a feasible, low-cost chip laboratory device, equipped with nanoporous films to connect two stacked vertical microfluidic channels. One of the channels provides the sample, while the second channel attracts the sample through the potential energy driving force.…”

“…In addition, the process is relatively simple and does not require skilled personnel or expensive manufacturing equipment. Therefore, it is hoped that this kind of equipment can be used as a reference in bacterial detection, and more stable enhanced substrates and portable devices can be developed as soon as possible to cope with the challenges brought by the application of POCT, and can gradually improve the ability to integrate concentrated bacteria [ 118 , 120 ].…”

Microfluidic hotspots in bacteria research: A review of soil and related advances

“…The SERS method has also been modified by including a disposable low-cost microfluidic chip device that uses a nanoporous membrane (Krafft et al, 2021). The device connects two stacked perpendicular microfluidic channels, one providing the sample and the other providing the driving force to attract the sample.…”

Application of Raman Spectroscopic Methods in Food Safety: A Review

“…Then, SERS spectra of pathogens captured on polycarbonate membrane were collected. This developed lab-on-chip device detected pathogens in tap water rapidly and cheaply [44]. Detection of E. coli, S. enterica, and L. monocytogenes was achieved by a combination of filtration, 4-mercaptophenylboronic acid (4-mpba), and SERS mapping (Figure 5A).…”